Verifying propagation of Routes and Update Message

• Checking R1’s routing table to see if it has the networks of the PCs.

R1#show ip route

As you can see, R1 has the entry for the networks which shows R, i.e., learned via RIP and has AD value of 120 with metric as 1 which means the network is just 1 hop away.

• Debugging the events of RIP to check the sent and received updates at R1.

R1#debug ip rip events

As you can see in the debugged events, Router R1 sends update through both the RIP enabled interfaces with the connected routes and is also receiving updates on both the interfaces that are being sent from R2 and R3 with their connected networks. Also, you can see the time-frame after the router R1 resends the update with the connected routes that is almost 30 seconds (update interval).

RIP (Routing Information Protocol) is a Distance Vector Routing Protocol (DVRP) which generally uses hop counts to find the best path to the destination.  By RIP, we will be talking about the RIPv2 by default. Since RIPv2 is a dynamic routing protocol:

• RIPv2 exchanges routes/networks by sending RIP updates on each RIP enabled interface. A RIP enabled router advertises its connected routes as well as the learned routes that are present in its routing table. 
• RIPv2 does not form neighbor ships, nor does it use any hello packets. Each router just simple sends the updates (Full/Periodic updates or Partial/Triggered updates) to a multicast address of 224.0.0.9.
• RIPv2 uses a hop-count metric, i.e., counting the number of routers that are needed to be crossed in order to reach the destination network. It allows at most 15 hop counts and 16 is considered to be infinity (inaccessible).