Cisco CCNP Enterprise 300-410 ENARSI – CCNP ENCOR (350-401) : SWITCHING PROPERTIES AND TECHNOLOGIES
- 8_1 CDP And LLDP
CDP is a Cisco probe Reactory protocol used to share information about directly connected Cisco devices. This is an OSI layer to function. If you want to enable it globally, you can use the CDP run command, and if you want to enable it per interface, you can use the Cdpenabled commands under the related interface. But CDP is active by default on most iOS versions. Okay in here, we have just two routers connected directly connected to each other. And if I type, for example, the Show CDP neighbors comment on router one, I will see the informations related to router two, such as its model, such as the interfaces connected to this guy to verify the CDP. As I told you. I’m using the show CDP neighbors command for example, in router one, if I’m typing the show CDP neighbors command, I’m seeing the device ID as router two, which is the host name of the remote device.
And I’m seeing that the local interface that I’m using when I’m connecting to router two is the Gig zero. And I can also see that I’m connected to the Gig zero port of the router two. And I can also see that this device is capable of R, which means that the router and I can also see the module of the device, which is Cisco 2900 rather okay. We can also use show CDP Neighbors detail command for verification, and we can see the IP address and the platform and the capability port ID and the version information that saved. Let’s go ahead with the LLDP link layer. Discovery protocol is used to share information about other directly connected devices, and that is an industry standout. Actually, that’s the same thing with CDP, but that’s the industry.
- 8_2- POE (Power Over Ethernet)
In our next section we are going to talk about Power or Ethernet technology. Power or Ethernet describes any of several standards or systems which pass electric power along with data on twisted pair Ethernet cabling. This allows a single cable to provide both data connection and electric power to devices such as wireless access points, IP cameras and VoIP phones. As you can see that in the figure we have a PE switch. Please pay attention that our layer two or three switch should be supporting PE to use with the PE support. And also our end devices should be supporting the PE technology to have power from the ports of the power Ethernet switch. We have two benefits of Poe. The first benefit of Pure is removing the need for cabling and secondly Pee removes the need for an extra adapter.
We have a switch and we have an IP phone connected to the second part of our switch. If the switch is supporting a PE and if IP phone is supporting PE as well, you don’t need an adapter and you don’t need to use the cable of the adapter as well to provide electrical communication to IP phone. But if the switch would not be a Poe switch, you should be using an external adapterant cable to provide power to the IP phone. We have two PU standards and they are ITER PU 802, three AF and 380. Let’s start with the three AF. First, this standard provides interoperability between different vendors. In the standard, the devices are supplied with DC power up to 15 four watt. The second standard is 380.
This standard is an improved version of three AF standard and can provide up to 25 watts of power to the devices, which can be increased up to 50 watts or more by nonstandard applications. This standard, also known as Poe Plus Two, and here are the power classes of the poe. PE and PE Plus powered devices are given a class of zero to four depending on the power they need. We have power class zero up to power class four and we have different power range as you can see that in the figure. And here is the description of each class. For example, class zero is the default class and classification unimplemented. Class one is very low powered, class two is low power, class three is mid power and class four is the high power class of the poe. Here is the configuring and the verifying of the poe.
To configure a Poe port in the switch interface mode, as you can see that in the figure, you need to type power inline auto, or you can type power inline Never which configures the switch port to automatically negotiate inline power labels or to turn off PE. If you want to turn off Pee on the port, you can use the Never command. On the other hand, you can use the Auto command. Poe feature is already enabled under interface modes for today’s most of iOS versions, so you don’t need type the power inline auto command most of the times. But if you want to turn off pure for a specific port, you can use the power inline never command to turn the pua off. If you want to check the status for verification, you can use the visual power inline command.
- 8_3- SPAN And RSPAN
In this section we are going to talk about span and Rspin. Span is a feature of Cisco catalyseries switch that extends the monitoring capabilities of existing network analyzers to a switched internet environment. So let’s take a look at the SPAN’s overview spin mirrors the traffic in a switch segment to a predefined spam port. A network analyzer connected to the spam port can monitor the traffic from any of the other catalyst switch ports. As you can see in the figure we have Ethernet five and ethernet nine ports of the switch. If you want to monitor the traffic coming to fifth port from the nine port we use the span feature and we use a network analyzer on the 9th port of our switch like a wireshark PC we have two types of span and they are local span and the remote span.
Local span mirrors traffic from one or more interface on the switch to one or more interface on the same switch. Please pay attention that local span is made on the same switch. Remote span is an extension of span called the remote span and RSPAN allows you to monitor traffic from source port distributed over multiple switch which means that you can centralize your network capture devices. RSPAN works by mirroring the traffic from the source port of an Rspend session onto a wheel and that’s dedicated for the Rspend session. This wheel and is then tracked to other suites allowing the RSPAN session traffic to be transported across multiple switch.
On the switch that contains the destination port for the session traffic from the Rspen session villain is simply mirrored up till the destination port. Here in the figure you can see the Rspend, here is the monitoring device and here is the affected device. If you want to monitor the traffic the source traffic you can use the monitoring PC on the forehand switch. As you can see the configuration of the local span is pretty straightforward and you can use the monitor session one and you can use the source and destination interfaces pretty straightforward and if you want to verify the configuration you can use the showminder command. Remote span configuration is easy also but there are a few steps different from the span config.
First you need to define a remote span villain to define it on the switch. You create the villain by using Villan and Villan number command, then you can use the description if you want. The third step is typing the remote spank command then on the switch one which our monitored host is connected to you can tap the monitor session one and source interface is gig one and watch the port on the RX under receive site. And we have another command in here and that’s Monroe session one destination and remote villain is our remote Moots Pen villain and which is 30 as you can see. And that’s the monitoring host and we are monitoring the traffic coming from router to switch from that way.
- 8_4- IP SLA
IPSLA is a Cisco proofreactory iOS feature that allows to collect information, for example, response time, latency jitter, and the packet loss about network performance in the real time. And here is the configuration of the IPSLA to configure the IPSLA for router one. For example, we are different defining an Ipslea proof first by typing IP SLA and for example a number which is one in here. Then we are defining an ICMP equal on the other one. What I’m doing is I’m sending ping packets to this interface of router three and I’m doing this action for each 20 seconds. The frequency commands shows the frequency of the ICMP packets that I’m sending for.
Then I’m using a schedule for my IPSLA and I’m typing Ipsley schedule one start time and now and life will be forever. I’m defining the time range that I’m using this Ipslea to verify the Ipslea configuration. I can use the Show Ipslea configuration command and I can check the target address, source address and operation timeout and enter number or some more information like that. The second method that I can verify the IPS configuration is using the Show IPSLA statistics commands and we can check the latest operations, target time, latest operation, returned code, number of success and number of failures, or some more information like that.