RIP Neighbor Establishing Packets

This is a RIP packet capture when initially forming adjacency. The setup we use is simple and has 2 routers with network 0.0.0.0 command which indicates advertise everything on every link.

Packet flow will be like the following.. (click on the images to view in full size)

It is very simple that only 2 broadcast packets are exchanged to form adjacency. Note that this is RIPv1 because it is the default when we enable RIP on a Cisco router.

Let's see the content of the packet.

Both routers are just broadcasting what they know but does not broadcast back to the same routes learned by neighbor because of the split horizon rule.

Let's enable RIPv2 by entering version 2 process level command on both routers.

Now we can see it uses multicast packets to exchange routing information. Only difference is that it shows the subnet mask.

Download the packet capture from here.