ACL RIPv2 UDP Port 520 Block Updates

RIPv2 uses Multicast 224.0.0.9 UDP Port 520.

Router0:(same on Router1)

interface GigabitEthernet0/0

ip address 192.168.2.1 255.255.255.0

ip access-group udp-520-block in

 

ip access-list extended udp-520-block

deny udp any any eq 520

permit ip any any

sh ip route

Router1 (note 192.168.1.0 is not in the Routing Table)

 

   192.168.2.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.2.0/24 is directly connected, GigabitEthernet0/0

L 192.168.2.2/32 is directly connected, GigabitEthernet0/0

   192.168.3.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.3.0/24 is directly connected, GigabitEthernet0/1

L 192.168.3.1/32 is directly connected, GigabitEthernet0/1

Router0 (192.168.3.0/24 missing)

    192.168.1.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.1.0/24 is directly connected, GigabitEthernet0/1

L 192.168.1.1/32 is directly connected, GigabitEthernet0/1

   192.168.2.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.2.0/24 is directly connected, GigabitEthernet0/0

L 192.168.2.1/32 is directly connected, GigabitEthernet0/0