Running 2 routing protocols

Unanswered Question
Nov 7th, 2007

In a hub and spoke network in order to migrate from RIP to EIGRP, i configure to run both protocols with EIGRP distance 170.

Is that a problem?

Can this might cause any problems?

What shall i do to face those problems?



I have this problem too.
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bvsnarayana03 Wed, 11/07/2007 - 02:35

Your question is not very clear. Looks like u r wondering if there would be any problems if redistributing in to either protocol. This may create loops.

But if u r not redistributing & runing a separate eigrp instance with same subnets, do compare ur routes & reachability before wiping out rip.

keller.oliver Thu, 11/08/2007 - 04:34

The AD is a parameter to decide which routing protocol you want to believe, therefore it's a bad idea to set EIGRP _AND_ RIP to the same AD.

Example :

You have a target network that is reachable thru a single 56k modem or via 3 gigabit networks.

With the default settings, RIP says : Use the modem (less hops), while EIGRP says : Use the gigabit way.

The AD of RIP is 120, EIGRP internal (to the AS) 90, EIGRP external (to the AS) 170.

So in case the gigabit route is announced as internal, it would be preferred over the RIP route.

In case the gigabit route is announced as external, the RIP route would be in the routing table.



yagnesh_tel Thu, 11/08/2007 - 12:28

If I understand you correctly then you are in the process of migrating from RIP to EIGRP and you have already configured EIGRP with AD of 170 in your network.

Now answering your questions:

Can this might cause any problems?

This should not cause any problem as EIGRP routes(with 170 AD)will be sitting idle in routers as long as RIP routes are present with less AD. This won't affect any normal router decision.

What shall i do to face those problems?

Before removing RIP from your network just make sure that all the desired routes are learned by routers through EIGRP. After confirming this, you can proceed for removing RIP and get back to normal EIGRP AD.



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