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Hi, I'm Bo with Free Code Camp. This networkengineering course was developed by Brian Farrell, and instructor with Edmonds college.It will prepare you to configure, manage and troubleshoot computer networks. Also, thecourse is a great way to prepare for a comp Tia's network plus exam. So let's start. Hello,I'm Brian ferrill. And welcome to pace I t's session on the introduction to network devices,part one. Today we're going to be talking about layer one devices, layer two devices.And then we're going to conclude with layer three devices. There's a fair amount of informationto cover. So let's go ahead and dive into this session. Of course, I'm going to beginwith layer one devices. Well, before I start talking about the layer one devices, we needto talk about the open system interconnection model, the OSI model, it was developed asa way to help disparate computing systems to communicate with each other.The OSI referencemodel has seven layers. layer one is the physical layer, layer two is data link. layer threeis network layer four is transport layer five is session. Layer six is presentation andlayer seven is application. We're going to be discussing the bottom three layers layersOne, two and three today. Now most devices do function at more than one layer of theOSI reference model. But when it comes time to determining where they fit into the model,you must first determine the highest level at which they operate, because that's wherethey fit into the OSI model.To do that, you must know what they do and how that relatesto the OSI model. And with that, let's talk about analog modems. The word modem is actuallyderived from a contraction of modulator demodulator. modems were developed to take a digital signalcoming from a digital node and convert it to an analog signal modulating the signaland placing it on a wire. In return, it would accept an analog signal from the wire andconvert it demodulating the signal back to a digital signal that the node can understand.modems were developed to create a connection between network segments via the public switchedtelephone network using the plain old telephone system.Now modems provide for a single connectionto a network. And they're only concerned about the wire in the wire resides on the physicallayer layer one of the OSI model, it doesn't care where the signal comes from, it justdoes its job. Then there's the hub. A hub functions as a concentrator or repeater inthat it doesn't care where the signal comes from, or where the signal is going. Kind oflike the modem, it takes an electrical signal that arrives on a port and replicates thatsignal out all of its other ports.Hub may have just a few ports, or it may have manyports in for a variety of reasons the hub is not very common anymore in the modern network.So now let's move on to layer two devices. The first layer two device that we're goingto talk about is the switch. A switch utilizes an application specific integrated circuitchip and a basic chip. The ASIC chip has specific programming that allows the switch to learnwhen a device is on the network and which ports it is connected to via that deviceslayer two MAC address. That's what makes a switch a layer two device, a switch may havejust a few ports or it may have many ports, kind of like the hub. And although a switchessmarter than a hub, it can still be very simple, or it can be highly complex and programmable.A switch can only communicate with local network devices. another layer two device that weneed to talk about our wireless access points.The whap whap is a specific type of networkbridge that connects or bridges, wireless network segments with wired network segments.The most common type of web bridges and 802 dot 11 wireless network segment with an 802dot three Ethernet network segment just like a switch a wire Access Point will only communicatewith local network devices. Now let's move on to layer three devices. And First up isthe multi layer switch. A multi layer switch provides normal layer two network switchingservices, but it will also provide layer three or higher OSI model services.The most commonmulti layer switch is a layer three switch, it not only utilizes an async chip for switching,but that async chip is also programmed to handle routing functions. This allows thedevice to communicate and pass data to non local network devices. A multi layer switchis a highly programmable and complex network device. A multi layer switch may have justa few ports, or it may have a lot of ports. They're not very common in the small officehome office network.Because they're really really expensive, you're more likely to findthem in an enterprise local area network. Now let's move on to the router. A routeris the most common network device for connecting different networks together, utilizing theOSI models layer three logical network information. That's what makes a router a layer three device.The router uses software programming for decision making, as compared to the switches use ofan ASIC chip. The router uses this programming to keep track of different networks in whatit considers to be the best possible route to reach those networks. A router can communicatewith both local and non local network devices. In most cases, a router will have fewer ports,then a switch. Now that concludes this session on the introduction to network devices.PartOne, we talked about layer one devices. We talked about layer two devices. And we concludedwith a couple of layer three devices. Good day. I'm Brian ferrill. And welcome to paceeyeties session on introduction to network devices, part two. Today we're going to discusssome security network devices. And then we'll move on to some optimization and performancedevices. And with that, let's go ahead and begin this session. And we will begin by talkingabout security devices. First up is the firewall. Now a firewall can be placed on routers orhosts in that it can be software based or it can be its own device. A firewall functionsat multiple layers of the OSI model, specifically at layers 234 and seven. A firewall can blockpackets from entering or leaving the network.And it does this through one of two methodsit can do it through stateless inspection, in which the firewall will examine every packetthat enters or leaves the networks against a set of rules. Once the packet matches arule, the rule is enforced in the specified action is taken, or it may use state fullinspection. This is when a firewall will only examine the state of a connection betweennetworks. Specifically, when a connection is made from an internal network to an externalnetwork. The firewall will not examine any packets returning from the external connection.It only cares about the state of the connection. As a general rule, external connections arenot allowed to be initiated with the internal network.Now firewalls are the first lineof defense in protecting the internal network from outside threats. You can consider thefirewall to be the police force of the network. Then there is the intrusion detection system.The IDs and IDs is a passive system designed to identify when a network breach or attackagainst the network is occurring. They're usually designed to inform a network administratorwhen a breach or attack has occurred. And it does this through log files, text messagesand are through email notification Friends, and IDs cannot prevent or stop a breach orattack on its own.The IBS receives a copy of all traffic and evaluates it against aset of standards. The standards that it used may be signature based. This is when it evaluatesnetwork traffic for known malware or attack signatures, or the standard may be anomalybased. This is where it evaluates network traffic for suspicious changes, or it maybe policy base. This is where it evaluates network traffic against a specific declaredsecurity policy. An IDs may be deployed at the host level when it's deployed at the hostlevel. It's called a host based intrusion detection system, we're hids more potent thanthe intrusion detection system is the intrusion prevention system. The IPS an IPS is an activesystem designed to stop a breach or attack from succeeding and damaging the network.They're usually designed to perform an action or set of actions to stop the malicious activity.They will also inform a network administrator through the use of log files, SMS, text messaging,and or through email notification. For an IPS to work. All traffic on the network segmentneeds to flow through the IPS as it enters and leaves the network segment.Like the IDSall of the traffic is evaluated against a set of standards and they're the same standardsthat are used on the IDs. The best placement on the network segment is between a routerwith a firewall hopefully, and the destination network segment. That way all the trafficflows through the IPS. IPS are programmed to make an active response to the situation,they can block the offending IP address, they can close down vulnerable interfaces, theycan terminate network sessions, they can redirect the attack. Plus there are more actions thatan IPS can take. The main thing is is that they are designed to be active to stop thebreach or attack from succeeding and damaging your network.Let's move on to the virtualprivate network concentrator the VPN concentrator. Now this will allow for many secure VPN connectionsto a network. The concentrator will provide proper tunneling and encryption dependingupon the type of VPN connection that is allowed to the network. Most concentrators can functionat multiple layers of the OSI model. Specifically, they can operate at layer two, layer threeand layer seven. Now outside of internet transactions, which use an SSL VPN connection at layer seven,most concentrators will function at the network layer or layer three of the OSI model, providingIPsec encryption through a secure tunnel. Now let's talk about optimization and performancedevices. We will begin by talking about the load balancer. a load balancer may also becalled a content switch or a content filter. It's a network appliance that is used to loadbalance between multiple hosts that contain the same data.This spreads out the workloadfor greater efficiency. They're commonly used to distribute the requests or workload toa server farm among the various servers in the farm, helping to ensure that no singleserver gets overloaded with work requests. Then there's the proxy server. A proxy serveris an appliance that requests resources on behalf of a client machine. It's often usedto retrieve resources from outside untrusted networks on behalf of the requesting client.It hides and protects that requesting client from the outside untrusted network. It canalso be utilized to filter allowed content back into the trusted network. It can alsoincrease network performance by caching or saving commonly requested web pages.Now thatconcludes this session on the introduction to network devices, part two We talked aboutsome security devices that you may find on your network. And we concluded with optimizationand performance devices that may also be present. Hello, I'm Brian ferrill. And welcome to paceI t's session on networking services and applications part one. Today I'm going to be discussingthe basics of the virtual private network. And then I'm going to move on to protocolsused by virtual private networks. Now, there's a whole lot of stuff to cover. So let's goahead and begin this session. Of course, I'm going to begin by talking about the basicsof the virtual private network. A virtual private network or VPN is used by remote hoststo access a private network through an encrypted tunnel through a public network. Once theVPN connection is made, the remote host is no longer considered remote is actually seenby the private network as being a local host. There are many advantages to that, but I'mnot going to cover them right now. Even though the network traffic may pass through manydifferent routes or systems, it's seen by both ends as being a direct connection.Theuse of the VPN can help to reduce networking costs. For organizations and business. Thecost reduction is partially achieved, because the VPN doesn't require the use of a dedicatedleased line to create that direct connection. There are several different types of VPNsthere is the site to site VPN, which allows a remote sites network to connect to the mainsites network and be seen as a local network segment. VPN concentrators on both ends ofthe VPN will manage that connection. Then there's the remote access VPN, which is alsocalled a host to site VPN. It allows select remote users to connect to the local network.A VPN concentrator on the local network will manage the connection coming in from the remoteusers. The remote system making the connection uses special software called VPN client softwareto make that connection. The third type of VPN is the host of host VPN, which is oftencalled an SSL VPN.It allows us secure connection between two systems without the use of VPNclient software. A VPN concentrator on the local network manages the connection. Thehost seeking to connect uses a web browser that supports the correct encryption technology,which is either SSL or more likely TLS. To make the connection to the VPN concentrator.It's time to discuss some protocols used by the virtual private network. The big protocolfor VPN is called Internet Protocol security IPsec, which isn't actually a protocol initself, but a whole set of protocols. IP sec works at layer three of the OSI model or above.It's the most common suite of protocols used to secure a VPN connection.IP sec can beused with the authentication header protocol or the H protocol. h only offers authenticationservices, but no encryption. So it authentic Kate's the user but there is no encryptionof the session, or ipset can be used with encapsulating security payload protocol orthe ESP protocol. ESP both authenticates and encrypts the packets. It is the most popularmethod of securing a VPN connection, both H and ESP will operate in one of two modes.The first mode is transparent mode, that is between two devices as in a host to host VPN,or they can be used in tunnel mode, which is between two endpoints as in a site to siteVPN, IP sec implements Internet Security Association and key management eisah camp by default eisahcamp provides a method for transferring security key and authentication data between systemsoutside of the security key generating process.It is a much more secure process. Then wehave generic routing encapsulation. gra G is a tunneling protocol that is capable ofencapsulating a wide variety of other nuts layer protocols, it's often used to createa sub tunnel within an IP sec connection. Why is that? Well, IP sec will only transmitunicast packets, that's one to one communication. In many cases, there is a need to transmitmulticast, which is one to some communication, or broadcast, which is one to many communicationpackets across an IP set connection. By using GRP we can get that accomplished.Then there'sPoint to Point tunneling protocol pptp. This is an older VPN technology that supports dialup VPN connections. on its own, it lacked native security features, so it wasn't verysecure. But Microsoft's implementation included additional security by adding gr E. Two pointto point tunneling protocol. Transport Layer Security is another common VPN protocol. TLSis a cryptographic protocol used to create a secure encrypted connection between twoend devices or applications. It uses asymmetrical cryptography to authenticate endpoints andthen negotiates a symmetrical security key, which is used to encrypt the session TLS haslargely replaced its cousin, secure socket layer protocol, and TLS works at layer fiveand above of the OSI model. Its most common usage is in creating a secure encrypted internetsession or SSL VPN. All modern web browsers support TLS now I just mentioned secure socketlayer or SSL. SSL is an older cryptographic protocol that is very similar to TLS. Themost common use is in internet transactions. Why? Because all modern web browsers supportSSL. But due to issues with earlier versions of the protocol, it has largely been replacedby TLS.SSL version 3.3 has been developed to address the weaknesses of earlier versions.But it may never again catch up to its cousin, the TLS protocol. Now that concludes thissession on networking services and applications part one, I talked about the basics of thevirtual private network. And then I talked about the protocols used by the VPN network.Good day, I'm Brian ferrill. And welcome to pace I t's session on networking servicesand applications part two. Today we're going to be discussing network access services.And then we're going to move on to other services and applications. As always, there's a fairamount of ground to cover.So let's go ahead and dive into this session. I will begin withnetwork access services. The first network access service that I'm going to discuss isactually a piece of hardware, the network interface controller or Nic, it can also becalled the network interface card. The Nic is how a device connects to a network. Thenetwork interface controller works at two layers of the OSI model at layer two whichis the data link layer. It provides the functional means of network communication by determiningwhich networking protocols will be used as in a Nic that will provide Ethernet communicationor Nic that will provide Point to Point protocol. It also provides the local network node addressthrough its burned in physical media access control address at layer one the physicallayer, the network interface controller determines how the network data traffic will be converteda bit at a time into an electrical signal that can traverse the network media beingused, ie it provides the connection to the network.Most modern computers come with atleast one built in Ethernet Nic routers and other network devices may use separate modulesthat can be inserted into the device to provide the proper network interface controller forthe type of media they're connecting to in the networking protocols that are being used.Another network access service is radius remote, authentic dial in user service radius is aremote access service that is used to authenticate remote users and grant them access to authorizednetwork resources. It is a popular triple A protocol that's authentication, authorizationand accounting protocol. It's used to help ensure that only authenticated end users areusing the network resources they are authorized to use.The accounting services of radiusare very robust. The only drawback to radius is only the requesters the end users passwordis encrypted. Everything else gets sent in the clear terminal access controller accesscontrol system plus or TAC x plus terminal access controller access control system pluspoint what a mouthful, it sure is easier to say. TAC x plus is a remote access servicethat is used with authenticate remote devices and grant them access to authorized networkresources. It is also a popular triple A protocol used to help ensure that only authenticatedremote network devices are using the network resources that they are authorized to use.With TAC x plus the accounting features are not as robust as those found in radius.Butall network transmissions between devices are encrypted with TAC x plus, let's moveon to other services and applications. First up is our AAS Remote Access Services. Now,RS is not a protocol, but a roadmap. Rs is a description of the combination of softwareand hardware required for remote access connection. A client requests access from an RS server,which either grants or rejects that access. Then we have web services, creating a meansof cross communication. Web Services provides the means for communication between softwarepackages or disparate platforms. It's usually achieved by translating the communicationinto an XML format, or Extensible Markup Language format. It is becoming more popular as systemsdiverged. Last up is unified voice services. This is creating a better voice communicationsystem. It's a description of the combination of software and hardware required to integratevoice communication channels into a network as in Voice over IP. That concludes this sessionon networking services and applications. Part Two. I began by talking about network accessservices.And I concluded with other services and applications. Hello, I'm Brian ferrill.And welcome to pace eyeties session on DHCP in the network. Today, we're going to be talkingabout static versus dynamic IP addressing. Then we're going to move on to how DHCP works.And then we will conclude with components and processes of DHCP. And with that, let'sgo ahead and begin this session. And of course, we begin by talking about static versus dynamicIP addresses. So how does a computer know what its IP configuration is? Well, more thanlikely a computer received its IP configuration from a Dynamic Host Configuration Protocolserver.Not only did the server give the PC an IP address, but it also told the PC wherethe default gateway was, and more than likely how to find a DNS server, a computer willreceive its IP configuration in one of two ways. Either statically, which means manuallyset or dynamically, which means through a service like DHCP static IP address assignmentworks fine for very small and stable networks, but quickly becomes unwieldly and error proneas the network grows and more nodes come on to the network. So let's talk a little bitmore about static IP addresses. The administrator assigned An IP number and subnet mask to eachhost in the network, whether it be a PC, router or some other piece of electronic equipment.Each network interface that is going to be available to connect to the network requiresthis information.The administrator also assigns a default gateway location and DNS serverlocation to each host in the network. Now these settings are required if access to outsidenetworks is going to be allowed, that would be through the default gateway. And if humanfriendly naming conventions are going to be allowed, and that way, you can more easilyfind network resources, and that would be through a DNS server. Now each time a changeis made, as in a new default gateway is established, each IP configuration on each host must beupdated. That's why it becomes rather cumbersome and complicated as the network grows. Nowwith dynamic IP addressing the administrator configures, a DHCP server to handle the assignmentprocess, which actually automates the process and eases management. The DHCP server listenson a specific port for IP information requests.Once it receives a request, the DHCP serverresponds with the required information. Now let's move on to how DHCP works. Here is thetypical DHCP process. Upon boot up a PC that is configured to request an IP configurationsends a DHCP discovery packet. Now the discovery packet is sent to the broadcast address 255255255255on UDP port 67. The DHCP server is listening to that port. It's listening for that discoverypacket. When the DHCP server receives the discovery packet, it responds with an offerpacket, basically saying hey, I'm here to help. Now the offer packet is sent back tothe MAC address of the computer requesting help, and it's sent on port 68. Once the computerreceives that offer packet from the DHCP server, if it's going to use that DHCP server, itreturns a request packet. That means it's requesting the proper IP configuration fromthat specific DHCP server. Once the DHCP server receives the request packet, it sends backan acknowledgment packet. Now this acknowledgement packet contains all of the required IP configurationinformation. Once the PC receives the acknowledgment packet, the PC changes its IP configurationto reflect the information that it received from the DHCP server.And that's the typicalDHCP process in a nutshell. Now let's talk about components and the process of DHCP.We're going to begin by talking about the port's use. Now, I already mentioned thisonce, but I'm going to mention it again because you need to know this. The PC sends its discoverypacket out on the broadcast address 255255255255 on port 67. That's UDP port 67. When the DHCPserver responds, it responds to the PCs MAC address, Media Access Control address on UDPport 68. That's important. Remember the PC uses UDP port 67. The DHCP server respondson UDP port 68. Then there's the address scope. The address scope is the IP address rangethat the administrator configures on the DHCP server. It is the range of addresses thatthe DHCP server can hand out to individual nodes. There's also what are called addressreservations. Now these are administrator configured reserved IP addresses. The administratorreserves specific IP addresses to be handed out to specific MAC addresses. Now these areused for devices that should always have the same IP address. As in servers and routers.If you did Do that there is the possibility that your default gateways IP address mightchange.Now the reason we use address reservation is this allows these addresses to be changedfrom a central location, instead of having to log into each device and change the IPconfiguration separately. Now part of the DHCP process are what are called leases. TheDHCP server hands out that IP configuration information, but it sets a time limit forhow long that IP configuration is good. This is called the lease. So the parameters areonly good for a specified amount of time.Now the administrator can configure how longthe leases are, there are also options that the administrator can configure. The firstone that's pretty obvious is the default gateway location. There's also the DNS server address,and the administrator can configure more than one DNS server location. And administratorcan also configure an option for the PC to synchronize with a time server. So the administratorcan configure a time server address. There are many more additional options, but thoseare the big three that you should remember. Now when a PC boots up, it does have a preferredIP address, that would be the IP address that it had the last time it booted up.Now hecan request that same IP configuration from the DHCP server. Now the administrator canconfigure the DHCP server to either honor that preference or to ignore it. Now underthe right circumstances, a DHCP server isn't required to reside on the local network segment.Now as a general rule, broadcast transmissions cannot pass through a router. But if there'snot a DHCP server on the local network segment, the router can be configured to be a DHCPrelay. When a DHCP relay, also called an IP helper receives a discovery packet from anode, it will forward that packet to the network segment on which the DHCP server resides.This allows for there to be fewer configured DHCP servers in any given network, reducingthe amount of maintenance that an administrator needs to perform.Now that concludes thissession on DHCP in the network, we started with static versus dynamic IP addressing.And then we moved on to how DHCP works. And we concluded with components and processesof DHCP. Hello, I'm Brian ferrill, and welcome to pace it session on the introduction tothe DNS service. Today we're going to be talking about DNS servers, DNS records, and we willconclude with a brief discussion on dynamic DNS.And with that, let's go ahead and beginthis session. We're going to begin this session with a talk about DNS servers. Now DNS isthe process that maps human friendly names as in www.google.com, to their appropriateIP addresses. Without DNS we would have to memorize all of the IP addresses that we wishedto visit. Now, DNS stands for Domain Name System, and it's very structured in nature.If the local DNS server apparatus doesn't contain the needed record, it sends the requestup the DNS chain until the positive response is received back. Now this positive responsegets passed back down to the original requester. Now DNS does require that an F q dn fullyqualified domain name is used in order for it to function properly known Fq dn is thewww.google.com it's that naming convention right there. The www is the specific servicethat's being requested.The Google portion is the local domain that contains the specificservice. And the calm is the top level that contains the Google that contains the specificservice that is an F q dn. Now that we've got that covered, let's talk about the differentlevels of DNS servers. First off, there can be a local DNS server. This is the serveron the local network that contains the hosts file that map's all of the Fq DNS to theirspecific IP addresses in the local sub domain, it may be present or it may not be present.Then there are top level domain servers, the TLD server.Now, these are the servers thatcontain the records for the top level domains, examples of top level domains are.com.orgdotnet.edu, so on and so forth. Now, each of these servers contains all of their informationfor their respective domains kind of in what do I mean by kind of, well, the TLD serversdo delegate down to second level servers, their information, they do that to ease theload so that the TLD server is not overloaded. But the TLD server is the server that is responsiblefor maintaining the record. Then there's the root server. This is the server that containsall of the records for the TLD servers. So if you're looking for a TLD, that is kindof unknown, you will actually go to the root server, which will then pass you on to theappropriate TLD. Then there are authoritative servers and non authoritative servers. Andauthoritative DNS server is one that responds to a request. And that authoritative serverhas been specifically configured to contain the requested information. an authoritativeresponse comes from a DNS server that actually holds the original record.So an authoritativeresponse comes from the name server that's been specifically configured to contain thatrecord, then there are non authoritative DNS servers. Now a non authoritative DNS serveris one that responds to to a request with DNS information that it received from anotherDNS server. A non authoritative response is not a response from the official name serverfor the domain. Instead, it is a second or third hand response that's given back to therequester. In most cases, when we send a DNS request, we get a non authoritative responseback. Now let's move on to the various DNS record types. The first record that we'regoing to talk about is the a record. Now the a record maps host names are Fq DNS to theirrespective ipv4 addresses.Closely associated with the a record is the a record or quadruplea record this maps that Fq dn to its respective ipv6 address. Then there's the C name record.Now, this maps a canonical name or alias to a hostname. What that means is that you canhave edcc.edu be the same as EDC dot o r g without having to maintain two sites, theEDC c dot o r g can be the canonical name for EDC c.edu. This works in part becauseof the pointer record the PTR record. It's a pointer record that points out to DNS thatthere is a canonical name. And finally, we have the MS record. Now, this record mapsto the email server that is specified for a specific domain. It is the record that determineshow email travels from sender to recipient. And now let's move on to dynamic DNS. Nowdynamic DNS or DNS permits lightweight in immediate updates to a local DNS database.This is very useful for when the Fq dn or hostname remains the same, but the IP addressis able to change on a regular basis.Dynamic DNS is implemented as an additional serviceto DNS and it's implemented through DD ns updating. Now this is a method of updatingtraditional names. without the intervention of an administrator, so there's no manualediting or inputting of the configuration files required. A ddns provider supplies softwarethat will monitor the IP address of the reference system. Once the IP address changes, the softwaresends an update to the proper DNS server. DNS is useful for when access is needed toa domain whose IP address is being supplied dynamically by an ISP or internet serviceprovider. That way the IP address can change But people can still get to the service thatthey're looking for.Now, that concludes this session on the introduction to the DNS service.We talked about DNS servers, we moved on to DNS records. And then we concluded with avery brief discussion about dynamic DNS. Hello, I'm Brian ferrill, and welcome to pace itsession introducing network address translation. Today, we're going to be talking about thepurpose of network address translation. And then we're going to discuss how network addresstranslation works. And with that, let's go ahead and begin this discussion. Of course,we're going to begin by talking about the purpose of network address translation.Networkaddress translation, or Nat solves a very serious problem of how to route non routableIP addresses. As a partial effort to conserve the ipv4 address space, the private ipv4 addressingspaces were developed, these address spaces were removed from the public ipv4 addressspace and made non routable across public ipv4 networks. And this led to the problembeing non routable prevents that private ipv4 address from communicating with remote publicnetworks. NAT very simply solves this problem. A router with Nat enabled will translate aprivate IP address into a routable public IP address. When the response returns to therouter, it passes the response back to the device that requested it. So now that we'vecovered the purpose, let's talk about how network address translation works. In Firstoff, we get to talk about the fact that there are two categories of Nat. First up is staticNat. With static Nat each private IP address is assigned to a specific routable publicIP address this relationship is kept and maintained by the NAT enabled router. When a device needsaccess outside of the local network.The router translates the local IP address to the assignedpublic IP address. And when the response comes back, the router will translate the publicIP address back into a local one. Static Nat is not flexible in leads to some scalabilityissues. An individual routable IP address must be kept for every device that requiresaccess outside of the local network. So as the network grows, you need to increase theamount of public IP addresses that are under your control. That gets kind of expensiveand kind of complicated. They developed dynamic Nat to resolve some of that issue. With dynamicNat the NAT enabled router dynamically assigns a routable IP address to devices from a poolof available IP addresses.When a device needs access outside of the local network. The routerperforms the NAT function only the public IP address comes from a reusable pool of publicIP addresses. That private IP address is assigned the public IP address from the pool and onceoutside accesses stop the routable IP address goes back into the pool to be reused. As initiallydesigned dynamic Nat was more flexible than static Nat, but it still led to some scalabilityissues. As more network traffic required access to outside networks. The pool of availablepublic IP addresses needs to increase or outside Access cannot be achieved. But thankfully,there is a solution to this. And that solution is called port address translation, or inCisco terms, that would be net with Pat.Pat is a type of dynamic Nat that was developedto increase the scalability of network address translation. When a local network device requiresaccess to a public network, the net enabled router dynamically assigns the public IP addressto the device. With the addition of dynamically assigning a port number to the end of thepublic IP address. The router tracks the IP addresses important numbers to ensure thatnetwork traffic is routed to and from the proper devices. Pat still requires a poolof public IP addresses. But the pool may only contain one public IP address, or it may containseveral for a large private network. This is the preferred method of implementing networkaddress translation for two reasons. First off, there's less public IP addresses thatare required. And it makes it easier for an administrator to maintain.Now let's talkabout Nat terminology, specifically about the types of addresses. And we begin withthe inside a local address, which is a private IP address on the local network. It is theprivate IP address assigned to a specific device. Then there's the inside global addressa public address referencing an inside device. The inside global address is the public IPaddress assigned to the inside device by the NAT enabled router allowing access outsideof the network.Then there's the outside global address, which is a public IP address referencingan outside device. It is the public IP address assigned to a device outside of the localnetwork. Then there's the outside local address, which is the private IP address assigned toan outside device. This is the private IP address assigned to the outside device bythe NAT enabled router on the interior of the local network so that the inside devicecan communicate correctly with the outside device.Now that concludes this session onintroducing network address translation. We talked about the purpose of network addresstranslation. And then we talked about how network address translation works. Good day.I'm Brian ferrill. And welcome to pace eyeties session on wind technologies part one. TodayI'm going to be talking about the public switched telephone network. Then I'm going to moveon to broadband cable. And I'm going to conclude with a brief section on fiber optics. Andwith that, let's go ahead and begin this session. Of course, we begin with the public switchedtelephone network. Before I begin with the public switched telephone network, let's talkabout what makes a win a win as opposed to a LAN. Well, as a general rule, if you ownand control the line that the data is using to get from one place to another, you arenot using a wide area network or when technology. On the other hand, if you are using a formof transmission that you don't own, as in you're leasing a line or you're paying forthe use of it, then you are likely using when technology.One of the most common physicalinfrastructures used in wind technology is the public switched telephone network, thePSTN due to its widespread availability, just about everybody has a telephone line beingrun to their house or to their building. An older technology but still somewhat validtoday for when technology is dial up. No dial up utilizes the PSTN to transmit network trafficas an analog signal. dial up does require an analog modem to format the network trafficcorrectly so it can be transmitted. Your maximum theoretical speed on dial up is 56 kilobitsper second. It's not very fast. Then there's ISDN integrated service. Digital Network ISDNis a digital point to point when technology that utilizes the PSTN. It's a completelydigital service, it requires the use of a terminal adapter or ta to make the connectionto the end nodes. This ta is often called a digital modem, but it's not it's a terminaladapter ISDN can use a primary rate interface or pri.Now the PRI is composed of 2364 kilobitper second B channels and once 64 kilobit per second D channel that D channel is usedfor call setup in link management. A pri can achieve 1.544 megabits per second speed, andthat is commonly referred to as a T one leased line. The most commonly implemented form ofan ISDN though is the Bri the basic rate interface, it uses only two B channels and one D channel,and the Bri can achieve speeds of up to 128 kilobits per second. Now ISDN is not as capableas a digital subscriber line or DSL, but it can often be implemented where DSL cannotbe installed. Speaking about DSL, let's move on to it. xx DSL is the term for generic DSL.DSL is a digital wind technology that utilizes the PSTN DSL does require the use of a digitalmodem. It uses a dedicated digital line between the endpoint in a class five central officeor CEO.Now in order for the most basic forms of DSL to be installed, you have to be within18,000 feet of the CEO. DSL is capable of carrying voice and data. When it does carryboth filters are put in place in order for the voice signal to come through without anyinterference. Now let's move on to the different types of DSL. In First up is symmetric DSLor sdsl. symmetric DSL is synchronous in nature. That means that the upload and download speedsare the same as DSL does not carry voice communication. So if you need voice service, an additionalline is going to be needed. As DSL is used by businesses that don't quite need the performanceof a T one leased line, but they do require the symmetrical upload and download speeds.more common than sdsl is ADSL or asymmetric DSL, it's asynchronous in nature. That meansthat the upload speed is slower than the download speed. ADSL can carry data and voice commonupload speeds for ADSL are 768 kilobits per second, with download speeds of up to ninemegabits per second.It is the most common implementation of DSL, in the small officehome office environment. Last up for DSL is VDSL are very high bitrate DSL, it's asynchronousin nature as well. It's used when high quality video in Voice over IP is necessary. VDSLis commonly limited to download speeds of 52 megabits per second with an upload speedof 12 megabits per second. That's a whole lot faster than ADSL. But VDSL is only possiblewhen you're located within 4000 feet of a central office.There is an exception to whatI just told you though, the current standards do allow for up to 100 megabits per secondspeed over the PSTN using VDSL. But in order to achieve that, you must be within 300 metersof the central office. Now that the PSTN is out of the way, let's move on to broadbandcable. Broadband cable is coaxial cable networking. It's a broadband connection to a locationdelivered by the cable company. Broadband cable can deliver voice data and televisionall through the same connection.And the way it works is the digital signal is deliveredto the head and this is where all the cable signals are received. The signal is then processedin format added and then transmitted to the distribution network. The distribution networkis a smaller service area served by the cable company. The distribution network architecturecan be composed of fiber optic cabling, or coaxial cabling, and or a hybrid fiber coaxialcabling or HFC. Unlike DSL, the bandwidth of the distribution network is shared by allof those who connect to it.This can lead to increase latency in congestion during busytimes. The final distribution to the premise is usually through a coaxial cable. The otherthing that you need to know about broadband cable is that all cable modems and similardevices must measure up to the ISP is required data over cable service interface specificationsor DOCSIS specification. If it doesn't measure up, you're not going to achieve the speedsthat you expect. Now let's conclude with fiber. Fiber Optic networking is using light to transmitdata and voice. This allows for more bandwidth over greater distances.Fiber Optic networkingis more expensive to install, but it's also less susceptible to line noise. The fibersynchronous data transmission standard in the United States is called the synchronousoptical network or sonnet standard. The international standard is called the synchronous digitalhierarchy are SDH. Both sonet and SDH defined the base rates of transmission over fiberoptic cabling, which are known as optical carrier levels. Dense wavelength divisionmultiplexing is a method of multiplexing several optical carrier levels together, up to 32of them into a single fiber optic cable, effectively increasing the bandwidth of that single opticalfiber. Instead of dw dm you could use CW dm, course wavelength division multiplexing. It'ssimilar to dw dm, but it only allows for up to eight channels on a single fiber. Whenfiber optic is delivered to the premise, it's usually delivered over a passive optical networkor upon upon is a point to multipoint technology that uses a single optical fiber that usedto connect multiple locations to the internet.The passive optical network uses unpoweredoptical splitters. Now that concludes this session on wind technologies. Part One, Italked about the public switched telephone network. Then we moved on to broadband cable,and I briefly ran through fiber optic networking. Good day, I'm Brian ferrill. And welcome topace I t's session on web technologies, part two. Today we're going to be discussing GSMand CDMA when connections, then we're going to move on to why max when connections andwe're going to conclude with satellite wide area network connections.There's a fair amountof information to cover. So let's go ahead and begin this session. And of course, I'mgoing to begin with the GSM and CDMA wide area network connections. All cellular carriersuse one of two methods for connecting devices to their networks, and those methods are notcompatible. Currently in the United States, at&t and T Mobile use the global system formobile or GSM standard to connect their devices to their networks. Both sprint and Verizonuse code division multiple access, also known as cvma, as their method of connecting tonetworks.In those two standards are not compatible. The majority of the rest of the world utilizesGSM as the method for cellular network access. Let me speak briefly about cellular networking.Cellular networking involves using the cellular phone system for more than just phone calls.Cellular networking has been around for a while and it originally wasn't known as this,but the first version of it is first G or one g cellular and it was only capable ofvoice transmissions as improvements came along. We got to GE that is cellular with simpledata transmission capabilities, as in text messaging, 2g edge offered some basic cellularnetworking connectivity and was a stopgap measure between 2g in third generation cellular.3g cellular is the beginning of cellular win networking, it's giving way to 4g cellular,which is still an emerging technology. 4g currently consists of both LTE and y max.As a special mention, we need to talk about evolved high speed Packet Access, which isHSPA. Plus, it was a stop gap between 3g and 4g networking. It's still available today.The current standard for HSPA plus allows for up to a maximum data rate of 84 megabitsper second.Now it's not quite as good as LTE, which is Long Term Evolution. LTE usesan all IP based core with high data rates. Now LTE is compatible with both 3g ny Max,the current standard for LTE allows for up to 300 megabits per second in download speeds,and up to 75 megabits per second in upload speeds. Now let me introduce you to why maxwhen connections, why max stands for worldwide interoperability for microwave access. That'sa mouthful. That's why we say y max. y max was originally developed as a last mile alternativeto use when DSL or cable was not available. It can provide an alternative broadband connectionto a fixed location. It uses microwave transmissions as an over the air method to transmit voiceand data. It does require line of sight between relay stations, but why max can be used tocover significant geographic distances. Also, many municipalities are exploring the useof y max as a means of providing reasonably priced broadband to their citizens withouthaving to wire every household. y max is often considered to be a type of 4g technology,because it is compatible with LTE networks.But why Max is not compatible with third generationcellular networks. It is time for us to conclude with satellite when connections. SatelliteWang connections are a type of microwave satellite networking. It uses microwave transmissionsas an over the air method of transmitting voice and data just like y mx, it can be aneffective means of extending networks into places that are hard to reach. It does usemicrowave radio relay as the method of transmitting data through the atmosphere. Just like whitemat, it requires line of sight relay stations, but it can cover even more distances thany max. Why is that? That's because it utilizes a satellite network. By the way, because ofthe distances that satellite transmissions can cover.This can lead to latency problems,think about it, the signals got to go from a terrestrial location, up to the satellite,probably over to another satellite and then down to another terrestrial station. That'sa significant amount of distance. And there's going to be some lag. I just talked aboutthe communication satellite there also known as comsats. These do form part of the microwaverelay network. COMM sets can use a variety of orbits, including the millennia. geostationarylow polar or polar orbits. The low polar and polar orbits are used to boost microwave signalsbefore sending the signal back to Earth.Now that concludes this session on wind technologiespart two. I briefly talked about GSM and CDMA when connections, then I moved on to why maxwin connections and then we concluded with satellite wind connections. Hello, I'm Brianferrill. And welcome to pace eyeties session on wind technologies part three. Today I'mgoing to briefly discuss Metro Ethernet when connections. Then I'm going to move on toleased line when connections and we're going to conclude with some common standards. Withthat, let's go ahead and begin this session. Of course, I'm going to begin by discussingMetro Ethernet when connections. A Metro Ethernet connection is when the service provider connectsto the customer's site through an RJ 45 connector. The customer will view that when connectionas an Ethernet connection while in reality the type of connection will be dependent uponthe level of service that has been purchased.The service provider may also use a varietyof different wide area network technologies behind the scenes, but the customer will alwaysview it as being an Ethernet connection. Metro Ethernet is commonly deployed as a wide areanetwork technology by municipalities at the Metropolitan Area Network or man level. Asin at the municipal level, it's time for us to discuss leased line when connections.Aleased line is a dedicated circuit or connection between two endpoints used for communication.When we're talking about it. A leased line is usually a digital Point to Point connection.A leased line can utilize either a plain old telephone service line, a Potts line on thepublic switched telephone network, or it can be a fiber optic circuit provided by a telecommunicationscompany. leased lines tend to be more expensive for the customer, as the circuit can't beutilized by any other entity. So the whole cost is borne by the customer because they'rethe only ones who get to use it. Most often, the speed of a leased line is limited by whatthe customer is willing to pay. There are some multiplexing technologies out there thatcan be used to increase the amount of channels that are provided on the connection. One ofthe leased line technologies that you need to know about is point to point protocol PPP.It is a common data link layer or layer two protocol that's used with leased line networks,PPP can simultaneously transmit multiple layer three protocols.It can transmit IP and IPx and appletalk, all at the same time, through the use of control protocols, which are actuallyspecific to the layer three protocol that's being transmitted. PPP can include a featurecalled multi link PPP, which allows for multiple physical interfaces to be bonded togetherand act as a single logical interface. This effectively increases the available bandwidthto that system. There are different types of leased line connections. In the UnitedStates, Japan and South Korea, there are t carrier lines.Each t line is composed of24 Digital Signal channels. These are often called digital signals, zero channels areDSO channels, each channel is capable of carrying 64 kilobits per second, the 24 dsos make upwhat is called a DS one channel. In Europe, we have e carrier lines, each line is composedof 30 Digital Signal channels. These are also called DSO channels, the 30 DSL channels alsomake up what is called a DS one channel. When we're talking about fiber optic speeds, weoften talk about optical carrier lines, or OSI lines. The OSI data rates per channelare established by both the sonnet and SDH networking standards. Sonnet is the UnitedStates standard, and SDH is the international standards. Interestingly enough, the OSI ratesare the same across the two standards, it's possible to multiplex multiple channels intothe same fiber using different methods.The first method is dense wavelength divisionmultiplexing dw dm, it allows for up to 32 separate channels on a single fiber cable,or you could use coarse wavelength division multiplexing, which allows for up to eightseparate channels on a single fiber optic cable. Let's conclude with common standards.The standards I'm going to be talking about are the speeds We begin with ti lines. A Tone is composed of 24 DSO channels, which are also known as a DS one, and it's capableof achieving speeds of up to 1.544 megabits per second.If that's not fast enough foryou, you can lease a T three line. It's composed of 28 T one lines. Now a T three line is alsoknown as a DS three, and it can achieve speeds of up to 44.736 megabits per second. If you'rein Europe, you might lease an E one line, an E one line which is composed of 30 DSLchannels can achieve speeds of up to 2.048 megabits per second. Just as with the UnitedStates, if that's not fast enough for you, you can lease an E three line which is composedof 16 e one lines, which gives you up to 34.368 megabits per second speed.Well, if T oneis slower than an E one, a T three is faster than any three. For all c lines. We have theOSI one, it's capable of 51 point 84 megabits per second in speed, then there is the OSIthree, which gives you up to 155.52 megabits per second speed. It's becoming more commonnow to see OC twelves. With those you get up to 622.08 megabits per second. If you wantgigabit type speed, you might consider leasing an OC 48 that gives you up to 2.488 gigabitsper second in bandwidth. Currently at the top of the line is the OSI 192. That givesyou up to 9.953 gigabits per second speed. So essentially 10 gigabits per second worthof bandwidth. Now that concludes this session on web technologies. Part Three, I brieflydiscussed Metro Ethernet when connections, and then I went on to a discussion about leasedline Wang connections. And then I briefly mentioned some common standards. Hello, I'mBrian ferrill, and welcome to pace it session on web technologies Part Four. Today I'm goingto be discussing the difference between circuit switched and packet switch networks.ThenI'm going to move on to a discussion comparing frame relay versus Asynchronous Transfer Mode.And then we're going to conclude with multi protocol Label Switching. There's a wholelot of ground to cover, not a whole lot of time. Let's go ahead and begin the session.Let's begin this session by talking about circuit switched and packet switched networks.Circuit switch networks have a dedicated circuit between two endpoints that is used for communication.While set up the circuit can only be used for communication between those ends. Circuitswitch networks are most common in networks with leased line communication channels. They'rebest used when there needs to be a fair amount of continuous data traffic between the twoendpoints.In what circuit switch networks, there is only one path for the data to take.On the other hand, in packet switch networks data is broken up into smaller chunks andmove through the network only to be reassembled at the other end. The data is routed usingthe destination address and the data may take different paths through the network that it'straveling through. As a general rule, packet switch networks are less expensive to maintain.Why? Because the user doesn't have to maintain a dedicated circuit 24 seven, they're onlypaying for what they're using. Now let's talk about the differences between frame relayand Asynchronous Transfer Mode. Frame Relay is a wind technology in which variable lengthpackets are switched across the network.Frame Relay is less expensive than leased lines.But frame relay can be made to look like a leased line through virtual circuits or VCs.A frame relay network will track a VC using a Data Link connection identifier to identifythe end of the VC. There are two terms associated with frame relay that you should be awareof. The first is access rate. That is the maximum speed of Frame Relay interface. Theother term is the committed information rate, the cir, that's the guaranteed bandwidth thata customer receives. So that's the minimum speed of that frame relay network, the accessrate may be higher, but the customer is always guaranteed the committed information rate.Now let's talk about Asynchronous Transfer Mode, also known as ATM. ATM is a wind technologyin which fixed length cells are switched across the network. These cells are always 53 byteslong. ATM can handle real time voice and video, because it's very fast, but it has poor bandwidthutilization.The small cell size reduces the efficiency of the technology. But ATM is veryfast even if it is inefficient. Common speeds on an ATM network are 51 point 84 megabitsper second and 155.52 megabits per second. Let's conclude with multiprotocol Label Switching.The acronym for multi protocol Label Switching is MPLS. MPLS is a topology that's growingin popularity. Why? Because it's scalable. Also it is protocol independent MPLS can beused to replace both frame relay switching and ATM switching. It can be used to packetswitch both frame relay and ATM network traffic. This allows MPLS to be used with both framerelay and ATM technologies. MPLS is often used to improve quality of service and flowof network traffic.It uses a label edge router to add MPLS labels to incoming packets ifthey don't have them. The label edge router then passes those packets on to a Label Switchingrouter or LSR router. The LSR forwards those packets based on their MPLS labels to theirfinal destination. Now that concludes this session on when technologies Part Four, Italked about the differences between a circuit switched and packet switch network. Then wemoved on to frame relay versus Asynchronous Transfer Mode. And we concluded with the briefdiscussion on multi protocol Label Switching. Hello, I'm Brian ferrill. And welcome to paceit session on network cabling part one. Today we're going to be talking about twisted pairnetwork cabling. Then we're going to talk about twisted pair network connectors.Andthen we will conclude with categories of twisted pair. I have a whole lot of information tocover and I need to get through this quickly. So let's go ahead and begin the session. Andwe'll begin by talking about twisted pair network cabling. Most people are familiarwith twisted pair cables because they are the standard in the modern LAN they are whatyou see most often when you're looking at network cable. twisted pair cables are composedof four pairs of wires contained within an insulating sheath. Each pair of wires is twistedtogether to reduce electromagnetic interference, which is called EMI. The twist rates differbetween the pairs to reduce cross talk between the pairs which is a type of EMI. The colorsof the pairs of wires are always white, orange, orange, white, blue, blue, white, green, green,and white brown, brown.Twisted pair network cabling comes in either unshielded or shieldedtwisted pair that would be UTP or STP. The difference is that STP has an additional shieldthat is either wrapped around each pair of wires are around all four pairs of wires.That shielding reduces the opportunity for EMI or cross talk, but it is more expensiveand a little harder to work with. Because it's not as flexible UTP or unshielded twistedpair is deployed in the network much more often than STP. There are also plenum andnon plenum types of twisted pair. Most twisted pair cabling is non plenum grade, but buildingcodes often call for plenum grade cable to be run in plenum spaces. No a plenum spaceis that area that is designed to assist in the air flow of a building for HVDC purposesand most often the planet Is that space between the false ceiling and the actual ceiling.plenum cable is jacketed in either a fire retardant cover or in a low smoke PVC jacket.plenum cables often have a polymer or nylon strand woven into the cabling or into thejacket to help take the weight of hanging cables.This reduces the chance for the cableto stretch which can cause the pair or pairs of wires inside the jacket to break. Twistedpair is usually either a straight through cable or a crossover cable, but it can alsobe used to create a rollover or console cable. A straight through cable is used to connectdifferent types of devices together, as in a computer to a switch or switch to a router.Well a crossover cable is used to connect similar devices together, as in a PC to aPC or a switch to a switch the straight through in crossover cable use different pin outsto achieve their connections. A rollover or console cable is often required to connectto the console port on a switch or a router. It is quite common for one end of the rollovercable to use an RJ 45 connector, while the other end utilizes an RS 232, also calleda DB nine connector. So now that I've mentioned those connectors, let's go on to twisted pairnetwork connectors.And we're going to begin with the rj 11. You don't see these very muchin what we think of as networking, but you do see them all the time. The rj 11 uses asixth position for a contact modular connector. That's a six p four c modular connector. Itcan carry data or voice and it's common usage is voice communication, telephony, all ofyour telephone jacks are our j elevens. Then there's the rj 45. This is the one that wealways think about when we think about networking with twisted pair of cabling. It uses an eightposition eight contact or eight p eight c modular connector.It can carry data or voiceand it's common usage is data networking, Ethernet, then there's the rj 48 C, it alsouses an eight position eight contact modular connector eight p eight c just like the rj45 is a matter of fact, it's often thought of as being an RJ 45. But it's used as theterminating connector at the demark point for T one lines. And as I said just a momentago, it's often confused with the rj 45 but the active pins are different. Then we havethe UTP coupler, the unshielded twisted pair coupler. It's used to connect UTP cables backto back and still maintain adherence to industry standards, you might still come across the66 block being used for network connections, but probably not.It's a punch down blockthat was initially developed to terminate in distributed telephone lines in an enterprisenetwork. So you might still see it for telephony, but it's getting a little bit harder to findit. It was also used in slower speed networks as it can handle data traffic that's ratedfor cat three cabling, much more likely you'll find a 110 block. Now this is a punch downblock that was developed to terminate and distribute twisted pair network cabling. It'scapable of handling the signaling requirements of the modern network. I mentioned the DBnine or rs 232 connector earlier.Well here we go. It is a nine pin D sub miniature connectordeveloped for asynchronous serial communication between nodes. It was a common type of connectorbetween a computer and an external modem. And as I said earlier, it often makes up oneend of the rollover cable, you might come across the dbx 25 also known as an Ei a 232,or rs 232 serial connector. It is a 25 pin D sub miniature connector developed for asynchronousserial communication between nodes just like the DB nine only it was larger it to provideda type of connection between a computer and an external analog modem. And it's even lesscommon than the DB nine.Now let's move on to categories of twisted pair. And we beginwith cat three cat three was rated for up to 10 megabits per second speed, that's 10base t networking and it had a maximum delay distance of 100 meters. By the way, unlessI specify all twisted pair cabling has a max distance of 100 meters, that 10 megabits persecond wasn't quite fast enough. So then we got cat five cat five is rated for up to 100megabits per second speed, that's 100 base t networking. And that still wasn't fast enough.So they developed cat five E to cat five, he is rated for up to one gigabits per second,that's 1000 base t.Now we have cat six, cat six is rated for up to 10 gigabits per second,that's 10 Gigabit Ethernet, or 10 gb E. And with cat six, you can only get that 10 gigabitsper second over a max distance of 55 meters. For some reason they thought they needed togo more distance than 55 meters. So they developed cat six a, it has the same speed readingsas cat six, but it has a max distance of 100 meters and you can still achieve that 10 gigabitsper second networking. Now that concludes this session on network cabling part one.I talked about twisted pair cabling. Then I talked about twisted pair network connectors,and I concluded with the categories of twisted pair cabling. Hello, I'm Brian ferrill, andwelcome to pace eyeties session on network cabling part two. Today we're going to betalking about coaxial cabling, and fiber optic cabling. There's a fair amount of ground tocover so let's go ahead and begin this session. And of course we're going to begin by talkingabout coaxial cabling.Coaxial or co x cabling is one of the oldest Ethernet standards fornetwork cabling. It was standardized in 1973. It's been used for baseband carries just asingle digital signal and it has been used for broadband carrying multiple digital signals.It is composed of a central conductor that is covered by an insulating layer, which iscovered by an outer mesh or foil layer, which is then finished off with an outer insulatinglayer. That inner metal mesh layer helps to protect against electromagnetic interferenceEMI, there are several different types of CO x cable. There is rG 58. It was used in10 base two networking, it could span a maximum distance of 185 meters and had a 50 ohms impedancevalue. It's no longer commonly found in the modern network. Then there's rG 59. It's commonlyused to provide a broadband connection between two devices over a short distance and it hasa 75 ohms impedance value. And it's only used for short distances because it leaks its signalit can't span very far. Then we have RG six, which is used for cable TV or broadband.Nowthe distance that RG six can span varies, but it still has a 75 ohms impedance value,and it's commonly used to make the connection to a cable modem by the cable company. Thereare two basic types of CO x cable connectors. There is the BNC also known as the bayonetmeal Councilman connector. You can also call it a bayonet connector. It is used with COx cabling, but is now considered obsolete. The connection from the cable to the devicewas achieved through a spring loaded twist lock type of connector. A BNC coupler canalso be used to connect to coax cable segments back to back much more common is the F connector.It's a threaded bayonet connector, and it's also used with CO x cable.An f connectorcoupler can be used to connect to coax cable segments back to back. Now let's move on tofiber optic cabling. So now let me describe fiber optic cabling. First off, it's relativelyexpensive and harder to work with than with other types of network cabling. It's not ascommon as other types either co x or twisted pair in the land environment. But it can resistall forms of electromagnetic interference and it cannot be easily tapped into. Thatmeans it's harder for people to ease drop on your network. missions. It also can coverlong distances at high speed. Fiber Optic cabling is designated by fiber type claddingsize. By the way, the cladding is what the light bounces down, and it's jacket size thatouter jacket that covers the cable. The size of the cladding and the size of the jacketare listed in micrometres. Most applications of fiber optic cabling require that the cablesbe run in pairs, one cable to send transmissions one cable to receive transmissions.The typeof connector used on fiber optic cabling can impact the performance of the transmission.There are two basic categories of connectors there is the UPC the ultra physical contact.This connector has a back reflection rating of around a negative 55 decimal loss. Thenthere's the AAPC the angle the physical connector, which has a back reflection rating of arounda negative 70 decibel loss, making it the better performing connector.Now let's talkabout fiber types. There's multimode fiber, which uses an infrared LED system to transmitlight down to the fiber. It sends multiple rays of lights down the cable at the sametime. It is used for shorter fiber runs under two kilometers. It is less expensive thanthe other type of fiber cable and then we have single mode fiber SMF it uses a laserdiode arrangement to transmit light down the fiber. It only sends a single ray of lightdown the cable. Even though my diagram depicts it is going straight, it still bounces downthe cladding but there's only one of them. It's used for longer runs that require highspeed and it can span more than 40 kilometers. So now let's talk about fiber optic cablesand connectors. In First up is the SC that is the subscriber connector or this squareconnector. You can also call it a standard connector. An easy way to remember it is stickin click it's a push pull type connector.Then we have the st the straight tip. Youcan also think of this as stick and twist. It is a spring loaded twist lock type of connector.There is also the LC which can be called the local connector or loosened connector or littleconnector. It's a type of connector that uses a locking tab to secure the connection. Similarto the LC is the mtrj the mechanical transfer register jack. It's a small form factor connectorthat contains two fibers. And that also utilizes a locking tab to secure the connection. Youmight also find a fiber optic coupler guess what it does, it's used to connect to fiberoptic cables back to back.Now that concludes this session on network cabling part two,I talked about coaxial cabling, and I concluded with fiber optic cabling. Good day, I'm Brianferrill, and welcome to peace I t's session on network cabling, part three. Today I'mgoing to be talking about media converters, and then I'm going to talk about some cablingtools that you should know about. And with that, let's go ahead and begin today's session.I will begin by discussing media converters. It is not uncommon to be in a situation wherenetwork contains more than one type of cabling.This can lead to a situation where there'sa desire to connect different types of media together in order to make a cohesive or singlenetwork. Thankfully, media converters are readily available. The issue of trying toconnect these disparate types of transmission together mostly comes into play when you'retrying to join a fiber optic transmission to a copper wire infrastructure. And that'sactually represented in the types of readily available media converters that are out there.The most common media converters will connect single mode fiber to Ethernet, or multimodefiber to Ethernet or single mode fiber to multimode fiber. And finally, there is a fiberto coaxial cabling media converter. You need to be aware that these devices are out thereto help you create a solid network. Now let's move on to cabling tools. So every technicianshould put some thought into the tools that are in his or her toolbox.It is often saidthat you get what you pay for. And that is very true with tools. While a good techniciancan get away with buying the most inexpensive tools, by spending a little more money fora better tool that can often make the task easier and ultimately make the technicianmore efficient. But you also need to be aware that you can spend more money than is necessaryand not utilize all of the features in a given tool. So you need to find that balance pointbetween spending too much money and not spending enough money to become a really efficienttechnician.Now let's move on to the tools themselves. And we'll begin with crimperscrimpers are used to place cable ends on cables. They can be designed to work with a singletype of cable, as in twisted pair wire with multiple types of cable. I've seen some crimpersthat have been able to work with RJ elevens rj 45 and with a coaxial f connector, nextstep or wire strippers. wire strippers are used to remove the insulating covers on wiresand cables. Many are designed to just cut through the insulation without damaging thecable contained within that insulation. But some are also designed to cut all the waythrough the cable so that excess cabling can be trimmed.When you're using those to cutinsulation, you need to be careful that you don't cut the underlying cable. Then thereare punchdown tools. These are used to secure cable wires in it punch down blocks. A goodpunch down tool will trim the ends at the same time as it places the wire in the punchdown block. Then there are cable testers. These are used to test cables for common problemsas in mis configuration of the ends or incorrect pin outs. Cable testers will often test forthe cable standard used either the T 568 A or the T 560 a b or they can tell you whetheror not you've created a crossover cable.Cable testers will test for shorts or breaks inthe continuity of the cable. Some types of testers can also test for cable length andquality. These type of testers are called cable certifiers. Then we have the TDR thetime domain reflectometer. Now this is a cable tester for copper cabling that can determinethe length of a segment and the electrical characteristics of the cable. Also, a TDRcan tell you where break is in a segment. A TDR is capable of performing all of thesame tests that a cable tester can. But they are much more expensive than a standard cabletester. This is where you can spend too much money and not utilize all of the featuresavailable in the tool. Let's conclude this with the OTDR the optical time domain reflectometer.It performs all of the same functions that a TDR can but it is specifically used forfiber optic cabling. Now that concludes this session on network cabling, part three. Ibriefly talked about media converters, and then I brought up some cabling tools thatyou need to know about.Hello, I'm Brian ferrill, and welcome to pcit session on network topologies.Today we're going to discuss what a topology is. Then we're going to discuss peer to peerand client server networking. And then we're going to talk about some common network topologies.And with that, let's go ahead and begin this session. So what is a topology? Well, a topologyis basically a map that can be used to describe how a network is laid out or how a networkfunctions.A network topology can be described as either being logical or physical. a logicaltopology describes the theoretical signal path, while the physical topology describesthe physical layout of the network. And you should know that a logical and physical topologydon't need to match. And with that, let's move on to peer to peer versus the clientserver networks. So are these really topologies? No, not really. They don't describe the signalpath or the physical layout of the network. But yes, they are topologies because theydo describe how the network function. So that's why they're here in this discussion. Now ina peer to peer topology, the nodes control and grant access to resources on the network.No one node or group of nodes controls access to a single specific type of resource.There'sno real server present. Each node is responsible for the resources it's willing to share. Noclient server topology differs. Network resource access is controlled by a central server orservers. A server determines what resources get shared, who is allowed to use those resources.And even when those resources can be used. Now, in the small office home office, it'scommon to find a hybrid topology.That's where a combination of peer to peer and client servernetworking is, you know, let's move on to some common network topology models. The firstone we're going to discuss is the bus. The original Ethernet standard established a bustopology for the network, both logically and physically. And what I mean by a bus topologyis the signal traveled along a predetermined path from end to end, it went from one directionto the other direction, and then it could come back. Now as time went on, the bus developedsome mechanical problems that led to the development of different physical topologies. But thelogical topology remained the same in order to maintain backward compatibility. So whenwe discuss Ethernet networks, the logical topology is always a bus topology, while thephysical topology can be different.So let's talk about the bus. Again, the signal traversesfrom one end of the network to the other, no break in the line breaks the network, theends of the bus line needed to be terminated in order to prevent signal bounce. And whatthat means is that if there was a break or the ends of the line were not terminated,when the signal got to the end, it would bounce back through and create a storm. In a bustopology, the network cable is the central point. Now kind of related to the bus is thering, it's a bus line with the endpoint connected together, a break in the ring breaks the ring.In a ring topology, it's common to use two rings multiple rings that can rotate the safeguardsagainst a break in one ring bringing down the whole network. Now ring topologies arenot very common anymore in the land. But they're still used in the wide area network, especiallywhen sonet or SDH is used. Moving on from the ring we have the star, the nodes radiateout from a central point.Now when a star topology is implemented with a hub, a breakin a segment brings down the whole bus, because the hub retransmits out all ports. Now whenit's implemented with a switch of braking, the segment only brings down that segment,it is the most common implementation in the modern LAN. Then there's the mesh. A truemesh topology is when all nodes are connected to all other nodes, that's a full mesh. Now,those aren't very common because they are expensive and difficult to maintain. But it'scommon to find partial meshes. That's where there are multiple paths between nodes. Noweveryone knows at least one partial mesh network and that would be the internet. Now let'smove on to the point to point topology.That's where two nodes or systems are connected directlytogether. Now if you're talking about two PCs, that's when they use a crossover cableto create a point to point topology. There's no central device to manage the connection.Now this is still a common topology when implemented across a LAN connection utilizing a T oneline. We also need to discuss point to multipoint.In a point to multipoint topology a centraldevice controls the paths to all other devices. This differs from the star in that the centraldevice is intelligent. Now wireless networks often implement point to multipoint topologies.When the wireless access point sends all devices on the network receive the data. But whena device sends its messages only passed along to the destination. It's also a common topologywhen implementing a win across a packet switch network. Now let's discuss MPLS MPLS is multiprotocolLabel Switching and it is a topology that's used to replace both frame relay switchingin ATM switching. It's a topology because it specifies a signal path in layout. MPLSis used to improve the quality of service and flow of network traffic. It uses labeledge routers, le RS which is MPLS labels to incoming packets if they don't already havethem know the Le RS and the labels and pass the packets along to lsrs Label Switchingrouter, these forward packets based on their MPLS labels. That's what makes this a topology.Now that concludes this session on network topologies.We discussed what a topology is.Then we discussed the differences between peer to peer and client server networking.And then I brought up some common network topology models that you should know. Goodday. I'm Brian ferrill, and welcome to pace I t's session on network infrastructure implementations.Today I'm going to be talking about design versus function. And then I'm going to talkabout categories of different networks. In with that, let's go ahead and begin the session.Let's begin this session by talking about the difference between design and function.when describing a network, you have a couple of different options are you describing itsdesign or its function? If you are going to describe its design, then the first placeto start is to describe its topology? Is it a bus network is it a star network or a pointto point but if you're going to describe how the network functions, then the first placeto start is to describe the category or infrastructure implementation of that network.And with that,let's move on to categories of networks. First up is the local area network or the LAN. Mostlands are encompassed by a single network address range, that address range may be brokenup into subgroups. Through the use of virtual local area networks. VLANs. A LAN can spananywhere from a small area like a single room to a whole building or a small group of buildings,the land tends to be the highest speed network, it is becoming more common to see 10 gigabitsper second networking on the land.The most common types of network on the land are the802 dot three or Ethernet and or the 802 dot 11 or wireless local area network. These arethe most common types of network found on the LAN then there is the Metropolitan AreaNetwork or the man, it is larger than land. Most often it contains multiple local areanetworks. mans or Metropolitan Area Networks are often owned by municipalities. When aman is owned by a private entity, it is sometimes called a campus Area Network, then there isthe win the wide area network.Now a win spans significant geographic distances, they canbe described as a network of networks in the best example of a win is the internet. Sohow do you tell when a man becomes a win? Well, as a general rule, if all of the infrastructureimplementation has a single owner, then it is not a win. If it's large, it'll be a man.And if it's not quite so large, it'll be a LAN.But it's really easy to tell a personalArea Network a pan. Why, because they are extremely distance and size limited. Mostoften a pan is a connection between only two devices. Common examples include a Bluetoothconnection between a keyboard and a computer that's a pan, then there are infrared or IRconnections between a smartphone and a printer. That's a pan. Another example of a pan isnear field communication, which is now becoming seen between a smartphone and a payment terminal.The pan tends to have low throughput of data and low power output, they don't consume awhole lot of power. As the distance between devices increase, the throughput on a panwill decrease.Now a couple of special categories of networks in first is the supervisory controland data acquisition network, the scatter network. Now a scatter network is a type ofindustrial control system or ICS that is designed to control large scale deployments of equipment.The control equipment is usually at more than one sight. Scatter is often deployed in energydistribution systems by utility companies. Scatter uses a distributed control systemor DCs to communicate with programmable logic controllers, PLCs and or remote terminalsto control the equipment and processes from a central location. So they have a centrallocation to control equipment that's at remote locations. Scattered networks are often proprietary,and often require additional training to understand them and operate them. The last special mentionon categories of networks is the media net. It's a network designed and implemented specificallyto handle voice and video. They are designed and implemented to remove quality of serviceissues like latency, or jitter that can occur in other types of infrastructure.A videoteleconference network, or VTC is an example of a media net. They are often implementedas its own infrastructure, or as a sub infrastructure of a larger network. That concludes this sessionon network infrastructure implementations. I talked about the differences between designand function of networks. And I concluded with a discussion on the different categoriesof networks. Hello, I'm Brian ferrill, and welcome to peace I t's session on the introductionto ipv4, part one. Today we're going to be talking about the purpose of IP addressing.And then we're going to move on to some ipv4 address properties.There's a whole lot ofground to cover, and we need to do it quickly. So let's go ahead and begin this session.Of course, we're going to start with the purpose of IP addressing. When Bob on network a wantsto view a webpage hosted on a server on network C, how does Bob's computer know where to sendhim? Well, somehow Bob has gotten that server's IP address, either an ipv4 format, or ipv6.IP addresses are the location of a PC or server or some other network device that identifiesit by both its network location and host location within that network. IP addressing providesa logical addressing scheme for our computers, so that they can communicate on networks.Being logical means that the IP address can be changed with minimal fuss at any time.Unlike the MAC address, or the media access control address, which is physically embeddedinto the device.On the other hand, IP addresses are programmed and are easily change. Nowthat we know the purpose of IP addressing, let's move on to sum ipv4 address properties.ipv4 is made up of a 32 bit binary number. That means there are two to the 32nd power,possible address combinations. That gives us 4,294,967,296. Possible address combinations.With all of these possibilities, a process needed to be developed to keep everythingneat and tidy. And most of all, find double the implementation of a subnet mask was theanswer. And I'll get to that subnet mask in just a moment. Something that you will finduseful is learning how to convert from binary to decimal. Now decimal is base two, thatmeans there are only zeros and ones, as opposed to the base 10 that we're all used to dealingwith.If you would like more information on how to convert from decimal to binary or binaryto decimal, you can go to that website that's listed under this heading. So now let's talkabout the initial properties of ipv4. It is a 32 bit binary number. As I said before,it's divided into four sets of eight called octets. These are separated by periods ordecimals. Each octet is eight bits which equals one byte. We often represent ipv4 addressesin a human friendly format. That's called dotted decimal. Now when we look at this address192 dot 168 dot 1.9. That is an IP address, but we don't know which portion is the networkor which portion is the host. To be able to resolve this, it requires the use of a mask,which determines or defines which portion is which this mask is called the subnet mask.And the subnet mask has the same format as the IP address, as in it's 32 bits, and it'srepresented in dotted decimal format.So let's take a look at how an IP address and subnetmask operate together. So we're going to begin with 192 dot 168 dot 1.9 with a subnet maskof 25525525 5.0. Now the 192 dot 168 dot nine is the IP address. Like I said, in the otherportion, the 25525525 5.0 is the subnet mask. And it's easiest to show how the subnet masksby converting that dotted decimal back into binary. So we can do that by deconstructingthe IP address. So the first octet would be one, one, followed by six zeros, that equals192. The second octet is 10101, followed by three zeros, that equals 168. That third octetsreally easy. It's seven zeros followed by a one. And then we have the fourth octet,which is four zeros, a one, two zeros and a one that equals nine. Now if we deconstructthe subnet mask, what we have is we have three octets that are full of ones and one octetthat's full of zeros that represents that 25525525 5.0.Now if we put the subnet maskunder the representation of the IP address, anything that's not covered by a one in thesubnet mask is a part of the host address. Everything that is covered by a one is thenetwork address. So what we have for that IP address is that 192 dot 168 dot one isthe network portion of the address. And the node portion of the address is the nine. Andthat's how the IP address and subnet mask work together to define the network and thenode. Now that concludes this session on the introduction to ipv4 part one, we talked aboutthe purpose of IP addressing and then we moved on to some ipv4 address properties. Hello,I'm Brian ferrill. And welcome to peace I t's session on the introduction to ipv4 parttwo. Today we're going to talk about classes of ipv4 addresses. And then we're going tomove on to Classless ipv4 addressing and we will conclude with a brief discussion on subnettingipv4 addresses.There's a whole lot of technical information to cover, so let's go ahead andbegin the session. Let's begin by talking about classes of ipv4 addresses. InternetProtocol Version four ipv4 is a binary addressing scheme that's used for networking. It wasinitially finalized as a standard in 1981. ipv4 is a common network addressing schemethat is still being deployed today. There is an issue though with ipv4. Because of itsstructure and the growth and popularity of the internet. Most of the world has run outof assignable ipv4 addresses. But thanks to some forethought, it's still a valid scheme.Today, we need to talk about classes of ipv4 addresses and we begin with a class a networkaddress. Class A networks have an address range of zero to 127 in the first octet, thatgives us addresses from 0.0 dot 0.0 up to 127.255255255.The first octet on the lefthas a binary representation that always begins with a zero. This gives us a possible 16,777,214host addresses and the subnet mask with a class a network is always 255 dot 0.0 dotzero then there are classes B network addresses, they have an address range of 128 to 191 inthe first octet, that means that class B networks can have a range of 128.0 dot 0.0 up to 191.255255255.The first octet on the left always has a binary representation that begins with a one zero.Now Class B network addresses give us a possible 65,534 hosts in the subnet mask used witha Class B network is always 255255 dot 0.0. Then there are Class C network addresses andthey have an address range in the first octet of 192 up to 223. That means that we havean address range of 192.0 dot 0.0, up through 223.255255255. And that first octet on theleft always begins with a one zero.Class C network addresses give us a possible 254post addresses or node addresses and the subnet mask with a Class C is always 25525525 5.0.The last class of address that you need to concern yourself with is the Class D networkaddress. It has an address range of 224 up through 239 in the first octet, which meansthat it can range from 220 4.0 dot 0.0 up through 239.255255255.In that first octeton the left has a binary representation of 1110. So the first four bits are always takenand they are always 1110. Now subnet masks are not defined for class the networking classthe network addresses are used for multicast communication. And finally, we have a specialclass of addresses Well, kind of a class of addresses, and that involves automatic privateIP addressing up PIPA. In some cases, the Dynamic Host Configuration Protocol DHCP processmay fail. In these cases, a node or host will self configure an IP PIPA address. Now withina PIPA address, the first two octets are always 168.2 54. And if you see that in your IP configuration,you know that you have a DHCP problem.So one of the first methods that they use toconserve the ipv4 address space was they broke them out into public and private IP addresses.public IP addresses are routable. And being routable means that each public IP addressis unique. There can only be one. Now public IP addresses are not flexible, you are assignedto your network space, you're not really given a choice what your public IP address is goingto be. And then there are the private IP addresses. These are non routable. They do not need tobe completely unique throughout the world. They only have to be unique on their network.The first one that we're going to discuss is the class a license, there is only oneclass a license, you have a possible address range of 10.0 dot 0.0 up through 10.255255255.Next up is the class B license.There are 16 possible network addresses, not networkingO's, but just network addresses available in a class B license. They have an addressrange of 172 dot 16 dot 0.0 up through 172 dot 31.255255. And last but not least is theclass C license. There are 256 Class C licenses with a possible address range of 192.1 68dot 0.0 up through 192.1 68.255255. Now private IP addresses is highly flexible. You get toassign the network space it's not assigned to you. Now let's move on to Classless ipv4.Addressing Now the classes of addresses actually limited the flexibility of ipv4.Part of thereason for that was that the first routing protocols required the class structure. Andyou would think that with over 4 billion possible IP addresses that we'd still have flexibility,but we really didn't. classless addressing, which is called classless inter domain routingor cider was developed to slow the growth of routing tables. It also slowed the exhaustionof ipv4 addresses, it also created much more flexibility, the subnet mask becomes fluid,it's not rigid with cider addresses. It does not affect the private address space rangesthough, even though the subnet mask is now fluid, you still only have those range ofaddresses available in with the introduction of classless addressing subnetting is nowpossible, and it's highly desirable. So let's take a look at how cider notation works. Andwe'll begin with 190 2.1 68 dot nine with a subnet mask of 25525 5.0. With that becomesis 190 2.1 68 dot 0.9 slash 24. That slash 24 represents all of the ones in the subnetmask. And that's those first three octets on the left that 255255255. And if you lookat that address, it's a Class C address, which always has a 25525525 5.0 subnet mask, butit now becomes fluid with cider, we can take it and we can make it a 190 2.1 68.1 28.0slash 23.And what that really represents that slash 23 is a subnet mask of 25525 5.128.0. And that gives us a network of 190 2.1 68.1 28.0 which actually gives us a host rangeof 190 2.1 68.1 28.1 through 190 2.1 68.1 29.2 54. That gives us 512 host addressesas opposed to the possible 254. Now the broadcast address for that network would be 190 2.168.1 29.2 55. So now let's move on to subnetting ipv4 addresses. So what is subnetting? Well,subnetting cuts address spaces into smaller pieces. It takes one range of addresses andsplits it.This creates flexibility and network design and creates efficiency in address spaceutilization. So let's take a look at an example of subnetting. This will involve a small officenetwork. So originally, we have a network address of 223 dot 15 dot 1.0 slash 24. Thisis a Class C private network and it gives us a possible 254 hosts available. Why only254 will because a host cannot be assigned to the network address which is 223 dot 15dot 1.0. And it can't use the broadcast address which is 223 dot 15 dot 1.255. In this example,with this network address, all the hosts in the network can see all the other nodes.Nowlet's say that for security considerations, you want to split this into two networks.Well, you can do this using sub netting. So what you do is you take that slash 24 networkand you create two slash 25 networks. And those would be 223 dot 15 dot 1.0 slash 25and 223 dot 15.1 dot 128 slash 25. In this situation, the first networks host addressrange would be 223 dot 15 dot 1.1 up through to 23 dot 15.1 dot 126. And why is that? Well,because you can't use the network address which is 223 dot 15 dot 1.0. And you can'tuse the broadcast address which is 223 dot 1.1 27. The second address range that wouldbe created through this subnetting process would give us a host range of 223 dot 15.1dot 129 up through 223 dot 15.1 dot 254. That's because you can't use the network addresswhich is 223 dot 15.1 dot 128. And you can't use the broadcast address which is 223 dot15 dot 1.255. Each of those subnets would have 126 possible host addresses. So you tookyour possible 254 hosts available in one network, and you broke it down so that you now havetwo separate networks, each that's capable of having 126 hosts. And that's an exampleof subnetting an ipv4 address.Now, that concludes this session on the introduction to ipv4 parttwo, I talked about classes of ipv4 addresses. I then moved on to Classless ipv4 addressingand we concluded with a brief discussion on subnetting ipv4 addresses. Good day. I'm Brianferrill. And welcome to pace IITs session on the introduction to ipv6. Today, we'regoing to be talking about the ipv6 address structure. And then we're going to move onto ipv6 network transmissions. And with that, let's go ahead and begin this session. Ofcourse, I'm going to begin by talking about the ipv6 address structure. Now, ipv6 is theanswer to the question of what do we do about running out of ipv4 addresses. Unlike ipv4,ipv6, will provide enough Internet Protocol IP addresses for the foreseeable future. Now,shortly after the creation of ipv4 and its implementation, the IAA na the organizationthat's tasked with assigning routable IP addresses, realized the available ipv4 address spacewould not be enough in very short order if nothing was done.The IAA na then said aboutcreating the replacement, and they initially started by working on IPv. Five. While theywere working on IPv. Five, they found that due to the popularity of the internet, whichwas increasing at that point in time that it wasn't going to be enough. So they scrappedIPv five and began working on ipv6. Now the i na is confident that ipv6 will functionas the replacement for ipv4 for many decades to come. Why are they so confident? Well,we'll get to that here in just a moment. Now, ipv6 works at layer three of the OSI modeljust like ipv4 does.Layer three of the OSI model is also known as the network layer,and its major focus is logical network and host addresses. ipv6, his job is to providelogical network and host addresses to devices. ipv6 is 128 bit binary addressing scheme asopposed to ipv4 is 32 bits. The 128 bits are grouped together in sets, with each set beingseparated by a colon. Now each of these sets is two bytes long and a byte is a bit forhuman readability kind of the binary ipv6 number is converted to hexadecimal that'sbase 16. With each hexadecimal number being equal to four bits.Now those four bits canactually be referred to as a nibble. Because it's half of a bite. An ipv6 address is eightsets of four hexadecimal numbers, each being separated by a colon. That means that thereare over 340 undecillion addresses available to ipv6. That's two to the 120/8 power, whichis roughly equal to 340 times 10 to the 36 power. See that number there? I'm not evengoing to begin to read that one to you. So now let's talk about ipv6 is local addressstructure for the local address. The first 64 bits on the left represent the local networkin the last 64 bits on the right always represent the host. The local address structure followsthe E UI or extended unique identifier format, specifically the UI 64 format for those hoststhat have a 48 bit Mac MAC address that 48 bits is actually padded with an extra 16 bitsto make it 64 bits in length, you can always tell a local address, which is also calledthe link local address as it always begins with an F v 80.With ipv6, every device getsboth a local address and it gets a global address. Now the global address is unique,there is only one and every device gets one, the host address is still always the last64 bits. But every device actually gets assigned to a global network. The network portion isactually composed of a routing prefix and a subnet. This portion of the global addressstructure follows the classless inter domain routing or cider convention, with the numberthat follows the slash denoting the routing prefix. That's the part of the extremely globalnetwork that you belong to. The subnet is composed of the bits between the prefix andthe EU I 64 host address. Global ipv6 addresses always begin in the range of 2000, up through3999 in that first group of numbers on the left. Now in most cases, the need for DynamicHost Configuration Protocol DHCP has been eliminated. When implemented, ipv6 will autoconfigure both the local and the global addresses that are required for their networks. Whena device first comes online, it will use the Neighbor Discovery Protocol NDP to discoverwhat the required network addresses are both the local and global addresses.This allowsdevices to configure its own ipv6 address without an administrator's intervention. Solet's talk about ipv6 notation. The 128 bit nature of ipv6 makes it cumbersome to writeout and it can take up unnecessary space. Because of this, some rules were developedto ease the burden and save space. When you're looking at a group of ipv6 numbers. Any leadingzeros in a set can be dropped. The thing to really remember about ipv6 is that only asingle set of consecutive zeros may be replaced with the double colon. Why is that? Well,because if you could do it more than once, how would routers and other devices know howmany zeros to pad in there. Even with this ability to shorten it? It's still difficultfor us to remember ipv6 addresses, but it is still easier to write out and it stillconserves space within systems. Now let's move on to types of ipv6 network transmissions.And we begin with the unicast. unicast is one to one communication. That is where aspecific device is sending network traffic to another specific device. unicast can occuron the local network, which remember always begins with FC 80 or it can occur on the globalnetwork.Then there's multicast, which is one to a few communication. With multicasta specific device is sending network traffic to a specific group of devices that have registeredreceive that traffic routers registered to receive multicast transmissions that involvethe routing protocols that they are programmed to use. With ipv6 multicast addresses alwaysbegin with an F F. Both ipv6 and ipv4 use both unicast and multicast transmissions.A unique type of transmission to ipv6 is any cast. Any cast is one to the closest communication.This is where a specific device is sending network traffic to a specific ipv6 addressthat has been assigned to multiple devices. The router only sends the communication tothe closest one, at least from its perspective. Any cast transmission involves implementingDHCP v six. Earlier I said we really don't need to worry about DHCP anymore, but that'sonly partially true. While ipv6 is capable of auto configuring its own local and globaladdresses in certain situations. That's not always desirable. DHCP v six version sic canbe configured to hand out specific ipv6 addresses Or duplicate ipv6 addresses when necessary.That's useful for when load balancing a network or when network and redundancy has been created.Or when you have a user that has a tablet, a cell phone and a laptop, and you want todeliver the transmission to the closest device the devices using at that point in time.Thatis where DHCP v six comes in handy. ipv6 and ipv4 are not compatible. But we can do what'scalled a dual stack configuration. That's where the network and devices on the networkreceive both an ipv6 configuration and an ipv4 configuration. Or we can use what's calledtunneling. There's six to four tunneling, which is used to encapsulate an ipv6 datapacket and an ipv4 datagram, allowing that ipv6 packet to travel across or through anall ipv4 network. 64 tunneling can also be called teredo tunneling. Now, that concludesthis session on the introduction to ipv6, I talked about the ipv6 address structure.And then I talked about ipv6 network transmissions.Hello, I'm Brian ferrill, and welcome to paceit session on special IP networking concepts. Today I'm going to be talking about the mediaaccess control address. And then I'm going to talk about the difference between collisiondomains and broadcast domains. And we're going to conclude with types of network transmissions.There's a whole bunch of technical information to cover. So let's go ahead and begin thissession. Let's begin the formal part of this session by discussing the media access controladdress. All networking interfaces come with their own special address already configured,that would be the media access control address the MAC address, the MAC address is oftenreferred to as the physical address or the burned in address of the interface. WhileMAC addresses may be changed or spoofed. Most often it's set by the manufacturer and neveractually changes. Now switches and other OSI layer two devices rely upon that MAC addressin order to get network packets to their correct destinations. The MAC address has a specificformat. Actually it has two specific formats. One is 48 bits in length, and the other is64 bits in length.And both of them are represented by hexadecimal numbers. Both formats can bebroken down into two parts, the organizationally unique identifier or all UI, in the extendedunique identifier, the EU II, the Institute of Electrical and Electronic Engineers, theI triple E assigns all electronic manufacturers their own Bo UI, which always makes up thefirst portion of the MAC address. Each manufacturer then assigns its own t UI to each device thatis produced. Usually it is the serial number of that device. Theoretically, no two interfaceswill have the same MAC address, I need to mention the EU I 64 format. ipv6 requiresthat the node address or the MAC address be in an EU ii 64 format.So that MAC addresshas to be 64 bits in length. If the EU II of the interface is only 24 bits in length,it is actually split into two parts in 16 bits of padding are added to create the EUI 64 format. Now let's discuss the difference between collision domains and broadcast domains.Before I can talk about collision domains and broadcast domains, I need to talk aboutcarrier sense multiple access with collision detection. All Ethernet networks use thistechnology also called csma. With CD when transmitting data in an Ethernet network,all Ethernet devices have equal access to the network media and are capable of transmittingdata at any time. This can lead to data collision With csma CD, a device listens to the carriersignal on the network media. If no other device is transmitting, the device is free to senddata. If another device sends data at the same time, a collision is possible, whichcan corrupt the data. The devices listen for collisions. That's the collision detectionpart. If a collision occurs, the devices will stop transmitting and wait a random periodof time before attempting to transmit again. To do this, they use what is called a backoff algorithm.With that out of the way, now let me explain what collision domains are.Collision domains are an area of the network where packets or network traffic can collide.There are some devices that break up collision domains, they can be broken up by switches,bridges and routers, but not by hubs. On the other hand, a broadcast domain is definedas all the nodes that can be reached by a broadcast transmission.All the nodes thatcan be reached reside in the same network. Broadcast traffic cannot pass routers. Sothe domain is also defined by the subnet mask in that subnet mask defines the network. Here'sa special note. Technically, ipv6 does not use broadcast transmissions. ipv6 replacesbroadcast transmissions with multicast transmissions. In what do you know, that's a good segue forus to discuss types of network transmissions. We're going to begin this section by talkingabout types of ipv4 network transmissions in First up is unicast. unicast is a specificsource address transmission going to a specific source destination address, it can be thoughtof as one to one communication, it's only two devices transferring data between eachother, then there's multicast transmission. This is where a specific source address transmissionis going to a set of registered destination addresses. This is one to a few communication.routers often use multicast transmissions to track their routes and to make changesto the routing tables. In finally their broadcast transmissions. This is where a specific sourceaddress transmission is going to all addresses on the local network. This can be consideredas one to all communication because all devices on the local network are going to be ableto receive this broadcast transmission.So let's move on to types of ipv6 network transmissions.In ipv6 uses unicast just like ipv4 does. ipv6 also uses multicast, just like ipv4,where ipv6 differs is with any cast transmission. Any cast is where a specific source addresstransmission is going to a specific ipv6 address that has been assigned to multiple devices.The router uses an algorithm to determine which MAC address that has that speciallyconfigured ipv6 address is closest in only that device receives the anycast transmission,any caste can be considered as one to the closest communication. That concludes thissession on special IP networking concepts.I talked about the MAC address, I talked aboutthe differences between a collision domain and a broadcast domain. And then I concludedwith a discussion on the types of network transmission. Hello, I'm Brian ferrill, andwelcome to peace I t's session on introduction to routing concepts, part one. Today I'm goingto talk about the purpose of routing. And then I'm going to move on to some basic routingconcepts. There's a fair amount of ground to cover, so let's go ahead and begin thissession. First up is the purpose of routing. The basic purpose of routing is to connectdifferent networks together to allow them to communicate and pass data traffic betweenthem. Most often routing protocols are how networks determine where to send network traffic.That's the routes that they will take. In these routing protocols build maps. Actually,they build routing tables that we'll get to that later, that they use for directing networktraffic.Routing is what makes this interconnected world function as well as it does. Networkingwould be pure chaos without it as we'd have no idea where to send traffic. Now let's moveon to some basic routing concepts. First up is static routing. Static routing uses administratordefined routes. Each router in a static routing configuration must contain the route. A staticroute from router a to router B requires that router B has a static route back to routera, in order for two way communication to take place. If we had a static route from A toB, and B didn't have one back to a, a could send traffic to B but b could not send trafficback to A.Now static routing is easy to set up in small networks. But it's not so easyto maintain. Networks change all the time. With static routing. When a change occursin routers, the administrator has to go around to each router and implement that change.Then there's dynamic routing. This is where routers use protocols in order to determinethe best route between two networks. The administrator determines which protocols will be used onthe routers. In order for the routers to communicate, they must all be using the same protocols.There is an exception to that. And that's route redistribution. An administrator canconfigure a router to take one dynamic protocol and transform it into a different routingprotocol to be used from that point on. This is the only case when routing protocols canbe different across the network.Routing protocols can be stacked within a router that meansthat there can be more than one dynamic routing protocol programmed into a router. dynamicrouting is very fluid and dynamic in it's what makes possible today's interconnectedworld. The next concept is the default route. The default route is the direction that arouter will send network traffic when there is no known route in the routing table. Thedefault route is assigned by an administrator, it is usually a designated interface on therouter or it is the next designated next hop interface. Then there is the routing table.The routing table is a list of known routes to all known networks. From the routers perspective,it is established by an administrator when static routing is used. It is dynamicallybuilt by routing protocols when dynamic routing is employed. Each routing protocol maintainsits own routing table.Different routing protocols may have different routes to the same network.The loopback interface is an administratively configured logical number assigned to a routerto ease administrative functions or routing processes. Often the loopback interface isa sign in an ipv4 address format, even when ipv4 isn't used on the router. Many routingprotocols have been designed to take the loopback interface into account when performing administrativefunctions. The loopback interface may be completely logical or a physical interface may be assignedto be the loopback interface.Let's move on to routing loops. A routing loop is a possibleproblem that can be created if interconnected routers have a breakdown in their routingalgorithms. When a routing loop occurs. network traffic keeps looping through the routersuntil some system or mechanism breaks the cycle. routing loops can create network congestion,or even bring down a network. routing protocols use multiple methods to prevent routing loopsfrom occurring. One of the main methods that they use is what's called the time to livefield for the TTL field. The TTL field keeps track of how long that packet has been inexistence and how far it is traveled. And after a specified amount of time or distance,it will inform the next router to drop it.This helps to prevent routing loops. Thatconcludes this session on the introduction to router concept, part one, I talked aboutthe purpose of routing. And then I moved on to some basic routing concepts. Hello, I'mBrian ferrill, and welcome to peace I t's session on introduction to routing conceptspart two. Today I'm going to be talking about routing metrics, routing aggregation, andthen I'm going to conclude with a brief discussion on high availability, we have a fair amountof ground to cover, not a whole lot of time. So let's go ahead and begin the session. Ofcourse, I'm going to begin by talking about routing metrics. It is quite common for thereto be more than one route available to a remote network.Routing protocols use metrics todetermine which route is the best route to reach those remote networks. Each routingprotocol will use its own set of metrics in determining which routes to which networksare placed in its routing table. The same basic metric may be used by different routingprotocols. But when this occurs, the metric is usually implemented in a different mannerthrough the use of different algorithms. The first metric that we're going to discuss isthe hop count. The hop count is the number of routers between two endpoints. This isdetermined from the sending routers perspective, the maximum transmission unit, or MTU, isanother metric that is used by routing protocols. The MTU is the maximum allowed size of a packetmeasured in bytes that's allowed through an interface. The standard MTU for Ethernet is1500 bytes. packets that exceed the MTU must be fragmented into smaller pieces, leadingto more packets leading to a slower connection. bandwidth is another common routing metricbandwidth is a measure of the speed of the network connection, the speed is commonlymeasured in either kilobits per second, megabits per second, or gigabits per second. Anothercommon metric is latency.Latency is a measure of time that a packet takes to traverse alink. When latency is implemented by routing protocols. The total amount of latency ordelay to go into in between two points is what is used in the metric the administrativedistance, or ad as probably the most important metric that's used on routers. The administrativedistance is the believability of a routing protocols advertised routes, different routingprotocols are considered to be more believable, or trustworthy than others. routers use thead to help determine which routing protocol to use when more than one protocol is installedon the router. The lowest ad of an advertised route will determine the protocol that's used.There are some common standard administrative distance. First up is the directly connectedroute. That's a direct link between two routers that has an ad of zero in it is the most believableor trustworthy routes.Next is the statically configured route. It has an ad of one externalBorder Gateway Protocol has an ad of 20. It's still fairly trustworthy. Internal II II GRPhas an ad of 90 it's not as trustworthy as BGP, but it is more trustworthy than OSPFopen shortest path first, which has an ad of 110. i s i s has an ad of 115. So not quiteas believable as OSPF but more believable than rip, which has an ad of 120. ExternalAIG RP has an ad of 170 in internal BGP, and I've never seen internal BGP use has an adof 200. Now if you see an administrative distance of 255 that means that that route is not believableat all.As a side note, the ad can be set by an administrator. So if you are runningboth OSPF and is is on a router But you want is is to be used you could actually set OSPFad to a higher number than is is and then is is would always be used before OSPF. Nowlet's move on to route aggregation. without some mechanism put in place, routing tableswould soon become very large and highly inefficient. through careful planning network administrator'suse a process called route aggregation to condense the size of routing tables, theydo so through the use of classless inter domain routing cider. To summarize routes to differentnetworks, route aggregation is common in networking. Let's take a look at an example of Route aggregation.Suppose we have a router that has the following networks on its serial zero slash one interface.It has 10.1 dot 1.0 slash 24 known on that interface 10.1 dot 17.0 slash 24 10.1 dot32.0 slash 24 and 10 dot 1.1 28.0 slash 24.All of those networks are known to that interfacethat s slash zero slash one interface. These routes are what are known as contiguous routes,they're all in line, they can be summarized are aggregated by a common sider entry inthe routing table. They could all be summarized by the following entry 10.1 dot 0.0 slash16. Now there is a warning about route aggregation. Route aggregation takes careful planning duringthe network design phase. That above example would not work if the serial interface oneslash one on that same router was connected to network 10.1 dot 2.0 slash 24. Becausethat new network makes those networks on on the zero slash one interface, non contiguousnetworks, all the known networks are no longer all in a row. This leads to the fact thatthe routes could no longer be aggregated or summarize. Let's conclude with a discussionon high availability. part of a network administrator's job is to ensure that networks remain up andactive for the maximum amount of time. In an effort to ensure that networks don't godown.Administrators often remove single points of failure. A single point of failure in anetwork is the point where a single failure will cause the network to cease functioning.Network administrator's often use high availability techniques in order to remove those singlepoints of failure. An example of a high availability technique is the use of redundant links tooutside networks. Hot standby router protocol hsrp is a specific example of a high availabilitytechnique. hsrp is a proprietary Cisco method of creating a fault tolerant link using twoor more routers, with connections outside of the local subnet. The two routers are connectedtogether as well as having connections outside of the local network. A virtual IP addressis created and shared between the two routers. devices on the network are configured to usethat virtual IP address as their default gateway for packets leaving the network.If a singlerouter goes down, the link outside of the network is still available. Another high availabilitytechnique is virtual router Redundancy Protocol vrrp. It is an IETF Internet Engineering TaskForce standard that is similar in operation to hsrp. That concludes this session on theintroduction to routing concepts. Part Two, I discussed some routing metrics. Then I movedon to route aggregation. And I concluded with a brief discussion on high availability. Hello,I'm Brian ferrill, and welcome to peace it session on the introduction to routing protocols.Today we're going to be talking about some of the differences between interior and exteriorgateway routing protocols. We will introduce some more routing concepts And then we willend with routing protocols in themselves.There's a whole lot of stuff to cover. Solet's go ahead and jump into this session. Let's begin with the comparison between interiorand exterior gateway protocols. Interior gateway protocols, or igps are a category of protocolsused within autonomy networks. Autonomous networks are networks that you control orthat are under the control of a single organization. The most popular IGP protocols are OSPF, openshortest path first and rip version two. That's routing information protocol version two.Now there is a special mention here. And that's is is which is intermediate system to intermediatesystem is is is popular with extremely large autonomous networks. Like an ISP. These areInternet Service Providers network. Exterior gateway protocols, on the other hand, area category of protocols used between non autonomous networks. So eg peas are used between networksthat are controlled by different organizations or entities. The most popular EGP protocolis Border Gateway Protocol. No, it's not uncommon for organizations to have more than one networkthat they are routing traffic between. These are called autonomy networks. Some IGP routingprotocols use an administrator defined autonomous system number or AAS number as one means ofidentifying which networks can directly communicate with each other.The autonomous system numberis not a metric, but a means of identifying a network that might possibly accept anothernetworks traffic. Something to remember is that the AAS is only significant within autonomousnetworks, and has no relevance outside of them. Now let's move on to more routing concepts.routing protocols can be classified by how they perform thorough routing, interior gatewayand EGP. routing protocols can be broken out into three other categories of protocols,which is designated by their main method of determining routes between networks. The firstclass of routing protocols are distance vector routing protocols.With distance vector routingprotocols, the routes are determined by how many routers exist between the source andthe destination, the efficiency of the links in the selected route is not taken into considerationwith distance vector protocols. Periodically, the whole routing table is broadcast out ontothe network, then there are link state routing protocols, metrics are used to determine thebest possible route between destinations doesn't really matter how many hops there are, oncethe route has been established.These protocols then only monitor the state of directly connectedlinks and only make changes to their routing tables. When changes to the links occur. Withlink state routing protocols, only changes in the link status are broadcasted in finallythere are hybrid routing protocols. These use aspects of both the distance vector andlink state routing protocols. Let's talk about the next hop. The next hop is the next routerin the path between two points. The next hop is often designated by an interface addressof the device that is receiving the data or by that routers name or by that routers location.The routing table is the database table that is used by a router to determine the bestpossible route between two points.Different routing protocols use different algorithmsto place routes in the routing table. The next concept is convergence. Convergence canbe thought of as steady state. convergence is measured in the amount of time that ittakes all of the routers in an autonomous system to learn all of the possible routeswithin that system. Faster convergence times are desirable as that steady state allowsrouting to occur more quickly. Now let's move on to the routing protocols themselves. Firstup is routing information protocol. version two rip version two. Rip is an IGP distancevector protocol. For a route to be placed in the routing table, it can be no more than15 hops away. A hop count of 16 is considered unreachable. It uses various methods includingthe hop count to reduce the chances of a routing loop occurring.Rip version two uses multicastaddress 220 4.0 dot 0.9. to advertise its routing table. Open shortest path first OSPFis the most popular IGP that's currently being used. It is a link state routing protocol.It uses the Dijkstra algorithm to determine the shortest path to a network. after itsinitial startup, it only advertises changes to its routing table making convergence muchfaster. It uses different types of link state advertisements or lsats to announce differentchanges or different operations. OSPF uses two multicast addresses 220 4.0 dot 0.5 or220 4.0 dot 0.6 depending upon the type of LSA, that it's transmitting, next up intermediatesystem to intermediate system or is is is is is a link state routing protocol like OSPFand similar to OSPF it to uses the Dijkstra algorithm, but it uses different metrics todetermine the best path is is is highly scalable and offers fast convergence is is is oftenfound within networks under the control of an internet service provider.Then there'sBorder Gateway Protocol BGP, it's an exterior gateway protocol. That's also a hybrid routingprotocol. It is considered the routing protocol of the internet. And as a hybrid protocol,it is often considered a path vector protocol, which makes it a hybrid. One of the metricsused is the number of autonomous systems that must be crossed, not individual routers, BGPis highly scalable, but has a very slow convergence time when changes do occur. As a special mention,I'm going to talk about enhanced interior gateway routing protocol, ie eigrp. It isan advanced distance vector or hybrid IGP routing protocol developed by Cisco in 2013.Cisco made AIG RP, an open source routing protocol and an effort to increase its usein autonomous networks.It uses aspects of both the distance vector protocol and thelink state protocol to build its routing table. Ei GRP has a very fast convergence time. Butit's not as popular as OSPF because OSPF has been open source longer than EEI GRP Ei GRPuses a neighbor table, which is directly connected routers, and a topology table to build itsrouting table. The protocol only announces changes to the routing table on multicastaddress 224 dot 0.0 dot 10 in order to reduce bandwidth consumption. That concludes thissession on the introduction to routing protocols. I talked about the differences between interiorand exterior gateway protocols that I mentioned some more routing concepts, and we concludedwith the routing protocols themselves. Hello, I'm Brian ferrill, and welcome to pace itsession on basic elements of unified communications. Today I'm going to be talking about unifiedcommunications.And then I'm going to move on to some Unified Communication concepts.And then I'm going to end with voice over IP. And with that, let's go ahead and beginthe session. Of course, I will begin this session by talking about Unified Communication.Now, unified communications is not encompassed by a single product or device. It's a growingcategory in the enterprise network. Unified Communication or you see is the set of productsand services that Attempts to provide a consistent single user interface and experience acrossdifferent media types in different devices, you see allows a user to send a message fromone type of media, as in email, and have that media received as a different type of media.That email could become a text message or a voicemail.So now let's talk about someunified communication devices. First up is the UCS server. These are specialized servers,which quite often are virtual in nature that are designed to implement Unified Communicationsolutions in the workplace. The UC servers work in conjunction with UC gateways. A UCgateway is a network device that is designed to translate between different signaling methods,as in a voice over IP gateway, which will translate an analog public switched telephonenetwork voice signal into a signal that can be understood on The Voice network. Thereare some other UC devices. any device that can be used in the implementation of a unifiedcommunication solution is considered a UC device. They may include but are not limitedto voice phones, email systems, video conferencing systems, and instant messaging networks. Nowlet's move on to some unified communications concepts. The first concept that we're goingto discuss is presence. Now presence is an indicator that is used to communicate thewillingness or ability of a user to accept communication.Common present statuses includeavailable online offline busy and do not disturb. Present services are an important serviceprovided in UC solutions, as they will track the individual users across multiple devicesand networks in real time through the use of multicast transmissions. Once a communicationsession has been established, multicast communication is dropped in unicast network transmissionsare used. Another UCX concept that you need to grasp is quality of service. Quality ofService techniques are implemented to improve Unified Communication by managing networktraffic. The most common implementation of quality of service is class of service CEOs.Seo S is a quality of service technique that's used to manage network traffic by groupingsimilar types of traffic and assigning a network priority to that traffic. As in Unified Communicationtraffic is given a higher priority than email, a six bit differentiated service code pointdscp is used in the IP header to establish the CEOs or class of service.Now let's moveon to voice over IP voice is one of the most common implementations in a unified communicationssolution. Through the use of a presence service. Calls can be routed to the correct locationfor where the user is out to important protocols used in voiceover IP are Session InitiationProtocol, sip, and real time Transport Protocol RTP. sip has two purposes. First, it is usedto establish a communication session between two endpoints. The other purpose is that oncethe session is completed, sip tears down that connection between the two endpoints duringthe communication session RTP is used as the transport call, helping to provide that qualityof service through SEO s to the endpoints. Now that concludes this session on the basicelements of Unified Communication. I talked about unified communications. Then I movedon to some Unified Communication concepts, and I concluded with a brief discussion onVoice over IP. Good day. I'm Brian ferrill, and welcome to pace it session on virtualizationTechnologies. Today I'm going to be discussing the difference between a hypervisor in VirtualMachine Manager, then I'm going to move on to components of virtualization, and thenI'm going to have a brief demo discussion on software defined networking, I have a wholelot of information to impart not a whole lot of time.So let's go ahead and begin thissession. Of course, I'm going to begin with hypervisors and virtual machine managers.So what is the difference between a hypervisor in a Virtual Machine Manager, the differencecould be nothing or the difference could be everything. Some people use the term hypervisor,very broadly, they use it to refer to any of the software that is used to manage virtualmachines. Others will differentiate between the two terms in this way, a hypervisor doesnot need a host operating system, while a virtual machine manager or VMM requires ahost operating system, such as Microsoft Windows, Apple OS X, or a Linux operating system. Well,the hypervisor can operate as its own operating system. With that covered, let's talk aboutsome of the components of virtualization.First up is the virtual desktop. A virtualdesktop is a virtual machine or VM that functions as a desktop. Now, any modern operating systemcan be run inside of a VM desktop, multiple virtual desktops may be hosted on or froma single host system. Then there are virtual servers, which surprisingly, is a virtualmachine that functions as a server. Any modern server operating system can be used in a virtualserver environment. multiple virtual servers may be hosted on or from a single host, guesswhat there are then virtual switches, firewalls, and routers. These are virtual machines thatfulfill the functions of the switch firewall and router.Virtual firewalls and routersare particularly effective when they're combined with virtual network interface controllers,or virtual NICs, and virtual switches to create virtual networks. Speaking of virtual networksan important consideration for when designing a virtual network is how that virtual networkis going to pass traffic to remote networks or networks outside of the host system. virtualizationby its nature leads to either an open and highly scalable network or a closed self containedsystem, it is possible to create a completely self contained network with all of the virtualcomponents and never have network traffic leave the host machine. But if there is adesire or need for that network traffic to pass beyond the host system, then that functionneeds to be specifically granted. A connection must be created between the host systems physicalneck, and the virtual networking equipment to allow network traffic to pass through thephysical host system. Next up software defined networking. Software Defined Networking orSDN is the process of allowing the administration and configuration of a network to be donedynamically.With SDN, the administrator uses a front end program to make adjustments tothe network. This program sends the instructions to the networking equipment, which is thenreconfigured to perform as the administrator desires. SDN can allow network administratorsto dynamically adjust network performance without the need to log into each individualdevice that needs to be adjusted to achieve the desired performance. SDN is consideredto still be an emerging technology. But SDN also works well for virtual networks and cloudcomputing.Now, that concludes this session on virtualization technology. I talked abouthypervisors and virtual machine managers. Then I moved on to a brief discussion on somecomponents of virtualization, and I concluded with another brief discussion on softwaredefined networking. Hello, I'm Brian ferrill, and welcome to pace eyeties session on storagearea networks. Today I'm going to discuss the justification for storage area networks.And then I'm going to talk about storage area network technology. And with that, let's goahead and begin This session, of course, I'm going to begin with justifications for storagearea networks.There have been several factors that have led to the increased demand fordata storage. One of them has been the dramatic decrease in the actual cost of data storage,it actually costs us less now for storage on a per gigabyte basis than it has in thepast. What has happened is that as the cost of storage has decreased, the demand for storagehas increased dramatically. Businesses are now generating and analyzing huge amountsof data in an effort to create a competitive advantage. Think Big Data, I'm sure you'veheard about big data recently, or this increase in data collection has led to an increaseddemand for storage capacity. Another factor is that as the demand for data has increased,it is needed to be more available, which means that there has been a need to be able to accessthat data from anywhere in the accessibility as needed to be increased as well, includingfrom non standard devices.A storage area network or sand can be a solution to the needfor both storage capacity, and high availability. There are several advantages to the storagearea network. First off is scalability, the amount of data that is being generated todayis huge. This has led to a need to store that data, the sin is more scalable than otheroptions. As your storage needs increase, the capacity of the sin can be easily increasedto meet that storage need. Then there's data availability, the demand has also increasedfor that data to be available at any time from anywhere. And a sand can play a vitalrole in creating that accessibility.One of the most popular implementations of a sandis to deploy it as part of a cloud computing solution. This increases the availabilityof that data that's being stored on the sand. And finally, there's optimization. As therequirements to store data are removed from application servers, those servers can thenbe optimized to run those applications much more efficiently. At the same time, data storageis also optimized. It's time now to discuss some sand technology. The storage area networkor sand, and the network attached storage or NAS often get confused with one another,but they are different.The sin is an actual network of devices that have the sole purposeof storing data efficiently. On the other hand, the NAS is a specifically designed networkappliance that has been configured to store data more efficiently than standard storagemethods. The difference is that a NAS is a data storage appliance that is placed on anetwork. Well as San is a network of data storage devices. It is not uncommon for aSan to contain multiple NAS devices. With all of that data storage capabilities, severaltechnologies have been developed to ease the transmission of that data. The first one thatwe're going to discuss is fiber channel, or FC fiber channel is a high speed network technologythat was originally developed to operate over fiber optic cables only. since its introduction,the standards have been modified to allow the use of copper cabling, in conjunctionwith fiber optic cabling. fiber channel is commonly used to connect to sands. When FibreChannel is implemented. It uses the Fibre Channel protocol RF CP, as its transport protocolto transmit scuzzy commands, so it transmits small computer system interface commands tostorage devices, as in the NAS appliances, so a sin implements FCP as opposed to TCPas its Transport Protocol when Fibre Channel is used.Another technology that was developedwas internet scuzzy, or I scuzzy, I scuzzy is an IP based networking standard that isused to connect data storage facilities in sans. I scuzzy allows for scuzzy commandsand processes to take place over longer distances. Then the original scuzzy implementation, jumboframes are also allowed within the San environment. jumbo frames allow for greater throughputof data by allowing up to 9000 bytes of data to be in a single frame. This can greatlyincrease the efficiency of a sin. As a comparison, the standard frame on an Ethernet network,it can only be a maximum of 1500 bytes. Now that concludes this session on storage areanetworks. I talked about the justification for storage area networks, and then I concludedwith a brief discussion on some sand technology. Hello, I'm Brian ferrill, and welcome to paceit session on basic cloud concepts. Today, we're going to be talking about cloud classifications.And then we will conclude with different types of cloud computing. There's a fair amountof information to cover. So let's go ahead and dive right in. I will begin our sessionwith a discussion about cloud classifications.Cloud computing is where the resources onthe network are not actually physical in nature, they are provided to the end user. Virtually,cloud computing can lead to a very fluid and dynamic environment, as the required resourcesare normally only provisioned or supplied as needed, and are decommission or shut downonce their use is done. Most often. These virtual resources are not owned by the companyor user that uses them, but are provided by a service provider.While cloud computingis highly configurable and changeable, it does have some basic structures that are usedin the classification of the type of cloud that is in use. The first classification ofcloud computing that we're going to talk about is the public cloud. This is where systemscan interact with services, and devices within the public cloud and on public networks, likeover the Internet, and possibly with other public clouds.The public cloud is where theservices that are provided are not just provided to a specific user, but are open for the publicto purchase in use, then there are private clouds. This is where system only communicatewith services and devices within a specific private cloud. A private cloud is essentiallyjust that private. The only users who have access to it are ones who are authorized touse it. The cloud classification can be hybrid, it can combine aspects of both the publicand private clouds. And last up, there are community clouds. This is where cloud servicesare used by private individuals, organizations or groups that have a common interest. Nowlet's move on to different types of cloud computing. Because of the nature of cloudcomputing, it is very configurable to the needs and desires of the purchaser of thecloud services. purchasers have many options beyond the type of cloud services that theywant to provision, they must also determine what type of service they are going to require.From the most basic of services to the most highly complex of services, the purchaserneeds to have a plan going into Cloud computing, in order for it to be efficient and effectivefor them.So now let's move on to some of those services that cloud computing can offer.First up is Software as a Service. The End User purchases the rights to use an applicationor software without the need to configure the virtual servers that will deliver theapplication to them. It is usually delivered as a web app or web application, open thenews from within a web browser. But not always. If you have a subscription to Microsoft Office365 you are utilizing software as a service. Then there is platform as a service or P asthe user is provided with a development platform for the creation of software packages withoutthe need to configure the virtual servers and the infrastructure that delivers it. Youare essentially renting server or computing power in order to develop your software packages.Pa is more complex than software as a service.In Finally we have Infrastructure as a Service.This is where the end user is provided with access to virtual servers configurable bythe customer, and other virtual network resources, their infrastructure is actually virtuallyprovided to them. This creates a highly configurable environment in which customers can createthe resources and the performance that they require. The End User supplies the softwarethat's going to be used on the IaaS network, or they purchase it as an additional softwareas a service service. As you could have guessed from that last statement, it's not uncommonfor the type of cloud computing being utilized by an organization to be a mix. Some departmentsmay rely upon in use Infrastructure as a Service. While the development team will only utilizea platform as a service service. Part of the advantage of cloud computing is that the purchaseronly needs to initialize and pay for resources as they are needed.In a private cloud situation,it is possible for an organization that is using it to actually own the cloud resources.If they do own the cloud resources, they may have it on site, or they may pay to have thoseresources hosted off site. That way they can offload the maintenance cost of maintainingthose resources. Now, that concludes this session on basic cloud concepts. I talkedabout different cloud classifications. And then I concluded with a brief discussion ontypes of cloud computing. Good day, I'm Brian ferrill, and welcome to peace I t's sessionon implementing a basic network. Today we're going to discuss plan the network and thenconfigure the network.There's a fair amount of ground to cover. So let's go ahead anddive into this session. Of course, I'm going to begin with plan the network. So you needa simple small office home office network, Craig just plugged two PCs into a single hub,and you have a very basic network. But does it achieve what you want? How do you knowif you don't have a plan? A network plan is vital when implementing any network more complicatedthan the most very basic of networks. That plan should cover what you are hoping to achieveand how you are going to get there. In addition to your expertise, you are also going to needinput from your end users. Nothing is quite so frustrating as delivering the network thatyou've planned and built, and having the customer tell you that it is not what they wanted,or needed.Let's talk about that network plan in a little bit more detail. The first thingthat you should do is create a list of requirements. Now in order to make that list, you need todefine why the network is needed. That will help you to define what network features arerequired, then you need to define the scope or size of the network. Once you have those,they will help to establish a budget to implement that network. Once you know why the networkis needed, and what features are required then you can work on network design. In networkdesign, you need to determine what equipment is needed to implement that network. Partof the design is also how the network will be organized and how shared resources willbe placed on the network. When you're planning the network something that you should alsoconsider are compatibility issues. You need to know what standards are in use now in whatstandards will there be in the future. Included in those compatibility issues our does anycurrent equipment that is required, needs specific cabling or connectors in order tobe installed.That is something that often gets overlooked. Your network plan also needsto deal with network cabling runs your internal connections, how many node connections willbe required and where How will you plan for future expansion? that future expansion ismore than likely going to require more internal connections you should build in some tolerancefor future expansion. Then you need to consider external connections. How will the networkconnect to the outside. Where will that when connection come into your building? And wherewill your equipment be placed so that it can reach those wind connections. That is alsopart of the network equipment placement plan. Part of that plan also needs to consider ifthere is a wiring or equipment closet and where it's going to be located.If you dohave a wiring or equipment closet, are there environmental considerations about placingthe equipment in there? Is it too hot? Is it too cold? Is it too humid? Or is it toodry? You need to think about those things when you're placing your network equipment.Your plan should also cover how network security will be implemented. Are there specific typesof firewall emplacement considerations for those firewalls? Will virtual local area networksbe required? And if so, how many? Also, how will your switch port security be implemented?All of these go into a successful network plan. Now let's talk about configuring thenetwork. Here are some network configuration considerations for you. First up, how willyour clients receive their internet protocol addresses their IP addresses, using staticIP address configuration creates a higher level of security. But it's harder to manage,you could use Dynamic Host Configuration Protocol DHCP to automatically assign IP addressesfrom a pre configured pool. But your security may be a little bit lower If you do so, ifyou do use DHCP, you might want to consider using MAC filtering.MAC filtering will onlyallow specified MAC addresses that physical burned in address onto the network. It isan effective security measure that kind of like static IP addressing, it can be difficultto control and manage especially as the network grows. Something else to consider is thatif a server will be hosted on the network that needs to be accessed from outside ofthat network, as in you're hosting a web server, then you're going to need a demilitarizedzone a DMZ. the DMZ is an area of the network in which outside connections are allowed.While the internal network remains protected from that outside traffic. A DMZ will requirea custom configuration of the firewall. In most implementations, two firewalls are used.But it's not necessary to use two firewalls. Talking about firewalls, firewall placementand configuration considerations. Our next most small office home office when connectiondevices, as in their cable modems or DSL modems include firewall services that are sufficientin most cases for those small simple networks. But if a DMZ needs to be deployed, the bestmethod is to introduce an additional router in firewall into the network with the DMZresiding between the wind equipment, and the new router firewall combination.Another aspectof deploying a DMZ is that port forwarding should also be used at the router firewalllevel. Port Forwarding is used to direct requests for specific resources, like a request fora web page to the computer that has the resource. Let's move on to wireless network configurationconsiderations. The first thing to consider in a wireless network is the name of the wirelessnetwork. That's the service set identifier, the SSID. Now the SSID can be set to broadcastin the clear. Alternatively, the SSID can be set for the broadcast to be hidden. Somepeople consider hiding the SSID broadcast as a security measure. But it really doesn'twork that way. It doesn't stop the broadcast. It only hides the broadcast.A packet sniffercan easily see those broadcasts and those broadcast packets can be easily interpreted.So hiding the SSID is not an effective security measure. But it does make things a littlebit more difficult. The next aspect of wireless network configuration that you need to consideris encryption. First off, I will say you need to have encryption on your wireless network.Not only that, but you need to turn it on. By default wireless routers and wireless accesspoints why apps do not have encryption enable it Add the minimum. Your encryption type shouldbe WPA to personal. That's at the minimum. Some wireless network equipment comes witha service that is called why five Protected Setup, WPS. And if it does, it's enabled bydefault, this should be turned off and not used as it creates a weakness in the wirelessnetwork. Why is that? Well, because WPS can be easily exploited by an attacker, the networkthat you implement may not be exactly what you planned. So document any changes to theplan. undoubtably, during the process of implementing that plan, some changes will be introducedsome by you in some by request of the end user.Always document those changes to theplan and have the end user sign off on them, then be sure to incorporate those changesinto the final network documentation. Now, that concludes this session on implementinga basic network. I talked about plan the network, and then I talked about configure the network.Good day. I'm Brian ferrill. And welcome to pace I t's session on analyzing monitoringreports. Today I'm going to talk about baseline reports. And then I'm going to move on tojust reports in general, I have a fair amount of ground to cover not a whole lot of time.So let's go ahead and jump into this session.And of course, I'm going to begin by talkingabout baselines. How do you know what constitutes good network performance and what indicatesthat an issue is about to happen. This is where baseline documentation comes into play.baseline documentation provides a snapshot of the network when it is running efficiently,at least hopefully, when it's running efficiently. baselines are usually kept as a log file.At the minimum baselines should be established on CPU utilization, and network bandwidthutilization. You may also base Mark other functions as you deem them to be relevant.network administrators should perform periodic tests against the baseline to check to seeif the baseline is changed, they will change over time. And in order for network administratorsto know what constitutes good performance on their network, their baselines need tobe current, you can use Windows performance monitor to help establish the baselines foryour network. Let's talk about some of the items that should be considered for baselinereports. First up is network device CPU utilization. Knowing the CPU utilization on a piece ofequipment can help to determine when a network device is going to fail.If your CPU utilizationis constantly at 100%, you know, there's a problem. That problem may be that it's goingto fail. Or it may be that you need to install more network devices to take care of a growingnetwork. But you won't really know that if you're not baselining the CPU utilizationnetwork device memory utilization should also be baseline. It can help to determine whenit is time to expand the memory of a network device.A good item for baselining is bandwidthutilization. This can help to determine the overall health of a network, it can help todetermine when network segmentation should occur. It can also help to determine if anetwork device is about to fail, particularly if it's creating a storm of data. baselineutilization reports can help identifying when a security breach has occurred, you mightwant to consider baselining your storage device utilization This can help to determine whenstorage utilization has become a bottleneck on the network, where your storage devicesactually causing the network to slow down because there's too much data being pushedinto it.Which means that baselining your storage utilization can help determine whento increase the storage capacity of that network. You might also want to baseline your wirelesschannel utilization. This can help to determine how saturated the wireless channels have become.Once it's been determined that your wireless channels are saturated, a new wireless accesspoint can be installed to alleviate the pressure and then you need to create a new baselinefor wireless channel utilization.This baseline can also help to determine if there is unauthorizedwireless access occurring on your wireless network, especially if there is utilizationon a channel that is not supposed to have any utilization. Now let's move on to analyzingreports. Before we talk about analyzing reports, let's talk about log file management. logfiles can accumulate data quickly. And unfortunately, some administrators only review log filesafter a major problem has occurred. In most situations, this is a case of too much informationat the wrong time. Good administrators will set the proper reporting levels with theirlogging software, they won't be logging all that debug information that level seven information,unless of course, they're actively debugging a system or application.Good administratorswill review log files and compare them against their baseline documentation. They do thisto find issues while the issues are still minor and before they become major. log filesshould also be kept and archived in case there is a need for historical data. When you doarchive your log files, you should follow the organization's data storage policy. somethingto consider is that you may want to create running graphs of important metrics that arecaptured by log files. graphing the data gives a quick visual reference making it easierto spot issues and trends. Many logging applications give the administrator the option of creatingthose graphs easily and quickly. But then again, they don't do you any good if you don'treview them on a regular basis. If you're having an issue with a router or link, oneof the first things that you want to do is you want to run an interface report.Now whenyou're reviewing the output from the interface report, the first line is usually a reporton the status of the link or that interface. If it says something like Fast Ethernet isup line protocol is up that's all good. That means that interface is up and active anda link has been established. If it says Fast Ethernet zero slash zero is up line protocolis down, guess what all is not good. The interface is administratively set up, but it is notable to communicate with the other end of the link. And there are several differentissues that may be the cause there. If that first line says Fast Ethernet zero slash zerois down line protocol is up all is not good. This down up status indicates that there isan issue on your end of the connection.In most cases, that's going to be a cable issueor with the physical port itself. In your final status option is Fast Ethernet is downline protocol is down. If you see that all is not good. But also all is not bad, at leastnot yet. The issue here is that the interface has been administratively shut down. If youwant that interface up, you need to issue the command to bring that interface up andthen check the status report again. If the link status of the interface indicates thatthere are no problems, as in it's in an up in up state, but something is not operatingcorrectly, then it's time to dig a little bit deeper into that interface monitoringreport. There are a lot of things that can happen on a network devices interface to causeissues. In most cases, you will be required to log into the device and run the device'sreport to determine the cause of any problems on that interface.One of the main culpritsfor creating an issue on an interface are speed and duplex settings. If there is a speedmismatch, the devices will not connect. And it's highly likely that your status will bein an up line protocol down state. If a duplex mismatch has occurred. This will cause intermittentissues, you will need to look at the errors counter in the output or input reports. Youalso need to look at the counter for dropped packets. If the device is discarding incomingpackets, then more than likely the device's CPU is being over utilized. So you may needanother device or that device is about to fail. If the device is dropping outgoing packets,then there is a bandwidth congestion issue on that interface. If the interface resetscounter keeps going up, that means that the interface keeps resetting itself, the mostlikely cause is a communications issue between the two endpoints that's forcing that interfaceto reset Now that concludes this session on analyzing monitoring reports.I briefly talkedabout baseline reports. And then I moved on to other reports that you should be analyzingto take care of problems before they occur. Hello, I'm Brian ferrill. And welcome to peaceI t's session on network monitoring, part one. Today we're going to be talking aboutthe why of monitoring. And then we're going to talk about tools to monitor the network.There's a fair amount of ground to cover. So let's go ahead and jump into this session.I'm going to begin with the why of network monitoring.How do you know what is goingon in your network? Is it healthy? Or is it about to crash? network administrator's reallyhate to be surprised by failures in their networks, especially ones that could havebeen foreseen and therefore kept from happening? How do they keep from being surprised? Well,they enact a plethora of procedures and tools to monitor their networks. And to keep trackof how those networks are behaving. They do this to reduce the surprise element. Now thatwe've covered the why of network monitoring, let's talk about tools that you can use tomonitor the network. One of the main tools that network administrators use to monitortheir networks are log files. all operating systems offer a means of viewing events thatoccurred to that specific machine. That also includes networking equipment.There havebeen some applications that have been developed to monitor systems and networks that alsogenerate log files, among other actions that they can take. log files can be used to helppinpoint when a problem occurred, and help narrow down the possible causes of that problem.log files can also be used to help create a baseline of network behavior so that youknow what to expect from your network. log files can usually be classified as being systemslogs, General logs, or history logs.As a general rule, log files are an after the factmeans of monitoring the network, and they're not very good at real time analysis. That'spartially due to the sheer amount of information that log files can generate. It's just toodifficult to keep track of that in real time. Now let's talk about some specific loggingtools that you can use. The first one that I'm going to talk about is Event Viewer. It'snot really a log file in itself. It comes with Windows Server in most other Windowsoperating systems, and this tool can be used to review windows log files. The most importantlog files that you can view from Event Viewer are application security and systems logs.Application logs containing events that are triggered by the actions of an application.For example, if you have live update enabled, it will create log entries based on actionstaken by live update. Then there are security logs.These contain events that are triggeredby security events. For example, some logs are created for successful and unsuccessfullogon attempts. Then there are systems logs. These contain events triggered by Windowssystems components, for example, it will create an entry for when a driver starts or failsto start in either situation in log entry will be created. Now let's talk about a nonMicrosoft log. And that would be syslog. syslog, was developed in the 1980s. And it providesdevices that normally would not be able to communicate with a means of delivering performanceand problem information to systems administrators. This permits there to be separation betweenthe software that generates the message, the storage of that message in the software thatanalyzes the generated message. This separation of function allows syslog to be highly configurable,and this allowed it to continue to be a vital tool for monitoring networks, even today.As a matter of fact, the Internet Engineering Task Force the IETF, like syslog so much thatthey standardized it in 2009 syslog can generate log messages based on the types of servicesthat are running And includes a severity level that ranges from zero the most severe, upthrough seven, the least severe syslog can generate a lot of log messages.Most networkadministrators configure it so that they only get alerted when a minimum severity levelhas been reached. As a matter of fact, you almost never want to capture debug log eventsunless you are actively debugging an application or service. Just because it generates so muchinformation. syslog can be configured so that network administrators receive their alertsvia text message or SMS message or by email, or they may even receive a voicemail message.Well, syslog is a cool tool. It's not the only one that's out there. There's also simpleNetwork Management Protocol SNMP. SNMP is an application layer protocol used to monitorand manage a networks Health Network or systems administrators configure monitors. These areoften called traps. on devices that view the operation of a specific item. As in is thatrouters interface up or is that routers interface down, the monitors periodically communicatewith a network management station or NMS through get messages.That's g t messages that theNMS sends out. The response from the monitors is stored in a management information base,or MIB, which is a type of log file. That administrator can custom configure the monitorswith set messages sent from the network management station. When an event occurs, as in the interfacegoes down, the trap is tripped and the event is logged SNMP. Just like syslog can be configuredto just log the event or it can be configured to contact the network administrator SNMPgives network and systems administrators the ability to provide more real time monitoringof a network's performance and health than their security information and event managementcm. It's a term for software products and services that combined security informationmanagement or sim and security event management Sam, si e m may be provided by a softwarepackage network appliance or as a third party cloud service.It is used as a means of monitoringand providing real time analysis of security alerts. That is an example of the securityevent management function the sim function, it can also be used as a tool to analyze longterm data in log files. That's an example of the sim function or the security informationmanagement function. Si m can be highly configured to the needs of the individual network. Nowthat concludes this session on network monitoring part one, I talked about the why of networkmonitoring. And then I briefly touched on some tools for monitoring the network. Hello,I'm Brian ferrill. And welcome to pace 80s session on network monitoring part two. Todaywe're going to be talking about active network monitoring tools. Then I'm going to move onto wireless monitoring tools. And we're going to conclude with environmental monitoring.We have a fair amount of ground to cover not a whole lot of time. So let's go ahead andbegin the session. Of course I'm going to begin by talking about active network monitoringtools.Port scanners are used to scan a network for open ports and protocols. The informationthat a port scanner gathers is vital information if you want to harden the network. Port scannersare a great method of finding vulnerabilities in the network infrastructure, allowing thenetwork administrator to plug those vulnerabilities before they become a security breach. I dohave to issue a word of caution. You should only use a port scanner on a network or systemthat you are authorized to scan. Port scanning is a possible sign of someone trying to breacha system in can lead to problems if you're not authorized to scan that system.You don'twant to have to try and explain to an information security specialist why you were scanningtheir network if you're not authorized to scan it. A little bit different than a portscanner are applications that use interface monitor Or packet flow monitoring. These areusually deployed as an active software tool to monitor and analyze network traffic withina network segment. They're commonly called packet sniffers or protocol analyzers. Theyallow for an in depth look at what traffic is on the network, and may reveal securityissues that the network administrator can then mitigate. They help to identify top talkerson a network segment. Top talkers are those nodes or applications that generate the mostamount of traffic, packet sniffers can help to identify top listeners on a network segment.A top listener is that interface or the interfaces that are receiving the most network traffic.Or put another way those interfaces that are utilizing the most bandwidth for receivingpackets.This can help an administrator when they have determined that load balancing mightbe needed on the network. Microsoft message analyzer and Wireshark are examples of freepacket flow monitoring tools. Now let's move on to wireless monitoring tools. And we'regoing to begin with the Wi Fi analyzer. A Wi Fi analyzer is a similar tool to a protocolanalyzer, but only for wireless networks. It sniffs out packets on wireless networksand gives you statistics on those packets that it sees. It can check for bandwidth usage,channel usage, top talkers, top listeners, etc. Just like a packet sniffer can. Wi Fianalyzers can also identify networks by passively scanning the radio frequencies to determinewhere traffic is coming from. Given enough time, a Wi Fi analyzer can also identify hiddennetworks, or those that you don't know about.A Wi Fi analyzer can also infer non beaconingnetworks. based on data traffic over the radio frequencies, they may not be able to discoverthe SSID but they can tell the network administrator that something is passing traffic there. Anothertype of wireless monitoring tool are wireless survey tools. They're most commonly used asa design tool for setting up high quality wireless networks. When used in conjunctionwith mapping tools, the survey tools can help to establish the required amount of accesspoints to get the proper amount of coverage, the ideal antenna placement and the optimumamount of channel overlap. Wireless survey tools can also help to identify possible sourcesof radio frequency interference, or RFI. Wireless survey tools are often used to eliminate wirelessnetwork performance and security issues before they ever have a chance to occur. Let's moveon to environmental monitoring. A network's health can be affected by more than just anetwork interface failing or a possible security breach. Network and systems administratorsalso need to be concerned about environmental factors.Some of those factors include thequality and quantity of electrical power being supplied to their equipment, in the amountof heat in the rooms that equipment is kept. And also with that the humidity level powermonitoring tools or systems and tools that can be used to evaluate the amount of in thequality of the electrical power being delivered to the system, they're often deployed withor alongside an uninterruptible power supply or ups. The monitor will issue an alert whenan issue with electrical power has been identified, giving the network or System Administratora chance to rectify the problem before any equipment has been damaged. All electricalcomponents are designed to operate within a specific heat range.Not only are they designedto operate within that heat range, but all electrical equipment will generate some heatwhile they're in operation. And the harder that equipment works, the more heat they willgenerate. This is where heat monitors come into play. The heat monitor allows an administratorto control the temperature levels before they become an issue. humidity is another itemthat network administrators need to keep in mind. Too little humidity increases the riskof electrostatic discharge or ESD. But too much humidity increases the risk of condensationon equipment and your electrical components do not like that condensation. Humidity monitorsallow administrators.