Help with CCNA SimulationTest Question 1

[CiscoTek]

I need to verify that I am answering this test question correctly and maybe some of you can help. The simulation has 3 routers... 2 of which (Router B+C)have already been configured correctly. The 3rd (Router A) needs to have RIP enabled and I will need to publish the other routes to this router.

Router A Router B RouterC
S0 192.168.134.1 S0 192.168.134.2 S0 192.168.10.2
S1 192.168.10.1

Here is what I put and it didn't work.
RouterA>#(config)router rip
RouterA>#(config-router)network 192.168.0.0

The show ip route displayed only the directly connected routes. I need to get the routes to publish to this router.

I looked further into this and I think I have the correct answer. the 192.168.134.x is a class C network and I designated a class B network of 192.168.0.0.

If I would have entered in this command would it have published the routes?

RouterA>#(config)router rip
RouterA>#(config-router)network 192.168.134.0

Your help is appreciated.

 

[hexn]

Funny how these routing protocols work....

When you specify the network command, you specify which interfaces will participate in RIP, NOT what subnets will be broadcasted. RIP broadcasts ALL routes it knows about out all interfaces participating.

SOOO, since you specified 192.168.0.0, you would THINK that S0 would participate in RIP since S0 does fall into that subnet/network.......or does it????

You see, RIP is funny about subnetting. The 192.168.0.0 network you specified will be read by RIP as a class C subnet, SOOOO since you have no interfaces in the 192.168.0.0/24 network, none of your interfaces are going to participate in RIP. The correct config would have been:

router rip
network 192.168.134.0

Clear as mud?

 

[CiscoTek]

It was clear enough. Thanks for your help. It is greatly appreciated.

Thanks again,

Assman

 

[spudnuts]

I'm confused, going for my CCNA on the 19th of December. You said "the 192.168.134.x is a class C network and I designated a class B network of 192.168.0.0."

How can 192.168.0.0 be a class B in any way???

Correct me if i'm wrong but isn't 128 - 191 the class B range?

router rip
network 192.168.134.0

I agree with this, or maybe

router rip
network 190.168.0.0
for a Class B

 

[CiscoTek]

I think inikis's previous point was that the RIP protocol looks to the local interface for where to find the routing table updates. This identification of the interface is not dependant on the class of the subnet.

If you enter in:

router rip
network 192.168.0.0

The RIP protocol looks for a interface with the IP address of 192.168.0.0 to recieve the routing updates. Since in the example above the only interface that has access to routing updates is 192.168.134.0, so the 192.168.0.0 would not work.

The only correct answer is:

router rip
network 192.168.134.0