In the below scenario, subnet is used for transit links between routers and is used for the user vlans situated on different floors. RIP version 2 runs on all three routers and additional static default routes are configured on R1 and R2 to forward internet traffic towards border router R3.

Network is up and running for more than few months without any complaints.


At some moment, the Fa0/1 interface on R1 (connected to users on Floor 1) goes down. Since no-one is working on this floor that day, the network administrator doesn't give priority to this issue and goes to lunch.
While on lunch, he receives phone calls from users on the other floor, Floor 2, complaining that the entire network experiences slowness, including communication toward the internet.

Considering the information that you have in the above diagram, could you try to indicate what is the problem ?

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Upon his return, the network administrator uses the following command on R1 and immediately spots the problem:

R1#sh ip protocols
Routing Protocol is "rip"
  Outgoing update filter list for all interfaces is not set
  Incoming update filter list for all interfaces is not set
  Sending updates every 30 seconds, next due in 13 seconds
  Invalid after 180 seconds, hold down 180, flushed after 240
  Redistributing: rip
  Default version control: send version 2, receive version 2
    Interface             Send  Recv  Triggered RIP  Key-chain
    FastEthernet0/0       2     2
    Serial0/0             2     2
    FastEthernet0/1       2     2
  Automatic network summarization is in effect
  Maximum path: 4
  Routing for Networks:
  Routing Information Sources:
    Gateway         Distance      Last Update         120      00:00:27          120      00:00:26
  Distance: (default is 120)

What solution(s) would you suggest to this problem?

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