Hello again, this is your host aviv's a Korea and in this case, which is our case number four, we're only allowing plus c networks that that is not Class C network that is not selected. Now when it comes to class C, we know that the first three bits of the first octet are reserved for class C, which is 110. So the first byte is 192. That would represent a Class C network. The first 21 bits are reserved for the network and the last eight bits are reserved for the host. So let's go ahead and apply this statement and see how it goes.
Let's console into r1 and just bring it up. Let me adjust the font okay. Okay, so we are here we have the routing table from before. Let's go ahead and just refresh it and do a show IP route. Okay, so we have the routing table here as you can see. We'll go into the global config mode country and apply it prefixed with a statement called T, IP route.
IP prefix list, statement, C permit. Please note that classic talks with 192 dot zero dot zero dot 03110 is the first three pizza reserved for class C greater or equal to 24 less than an equal to 24. And that's the subnet mask for class C. Now we will apply today router Ei GRP 10, which is our routing. protocol, distribute list. prefix statements see and it's in Word. And thank you interfaces FA zero slash slash one, exit and exit.
And let's save the configuration. As you can see synchronization is happening for the routing tables to come Options established. And now I can see my IP route is much more smaller and all those other routes are all gone. That had Class C on them. Thank you. So I want to show you if we do show running config and you can see all the statements that we applied.
Okay networks all the statements are here for the class p network and 14 Allow the last statement which was to allow Class C network. I hope this was very useful to you and this is how we apply apply prefix list and we filter the routing tables. Okay, we and we can filter routes display this is another tool that we can use and and prefix list is really very helpful to get rid of all the routes that are unwanted in the network as I mentioned earlier and and it keeps the networking more efficient as you know the routers take more CPU power to pick up the routing table