Cisco RIP filtering routes with Prefix-Lists

Cisco RIP filtering routes with Prefix-Lists:

Here is the topology for this example:

We will configure R1 to filter the routes that come from R3:

Before the configuration:

R1#show ip route rip

     100.0.0.0/22 is subnetted, 1 subnets

R       100.100.100.0 [120/4] via 192.168.13.3, 00:00:22, FastEthernet0/1

We configure RIP filtering with prefix-lists on R1:

router rip

 version 2

 network 192.168.0.0

 network 192.168.12.0

 network 192.168.13.0

 distribute-list prefix FILTER gateway GW-R3 in

 no auto-summary

!

ip prefix-list FILTER seq 10 permit 0.0.0.0/0 le 32

!

ip prefix-list GW-R3 seq 5 deny 192.168.13.3/32

ip prefix-list GW-R3 seq 10 permit 0.0.0.0/0 le 32

After the configuration:

R1#show ip route rip         

     100.0.0.0/22 is subnetted, 1 subnets

R       100.100.100.0 [120/10] via 192.168.12.2, 00:00:04, FastEthernet0/0