Unanswered Question
Jun 25th, 2007

I recently become network administrator of a network of 50 nodes. I realised that the previous guy was using RIP v2. As i know EIGRP is better(since all the devices are Cisco) and i tried to change it. The problem is that when i tried to changed(first from the remote Routers) i lost the telnet connection with the router i put the EIGRP routing protocol.

Why is that. Please help .


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 4.5 (6 ratings)
royalblues Mon, 06/25/2007 - 09:53


The best way to migrate would be to change the administrative distance of EIGRP while configuring to any value greater than the AD of RIP i.e 120.

Once you have done all the configurations and see all the routes properly, change the administrative distance back to the default value.

HTH, rate if it does


Edison Ortiz Mon, 06/25/2007 - 10:02

On the exec mode, type

config t

router eigrp [AS #]

under the router eigrp

R1(config-router)#distance eigrp ?

<1-255> Distance for internal routes

moses12315 Mon, 06/25/2007 - 10:27

ok that's good but when i try to reduce the AD of EIGRP is going to happen the same, mean loose telnet connections with the remote routers. Also if i follow that migration then because the EIGRP will have greater AD will not work at all because all the routing routes in the routing table will belong to RIP right.


srue Mon, 06/25/2007 - 17:56

If you telnet to the device you're working on from a directly connected device, whether it's a switch or another router, you shouldn't lose connectivity because you're coming from a 'connected' route.

moses12315 Tue, 06/26/2007 - 05:42

Actually imaging that we have 4-5 routers where router1 is where i am connected . And then goes 2-3-4-5 where 1-2 directly connected then 2-3 etc.So in order to go from 1 to 5 we use RIP v2. All the routers have RIP v2. I telnet to Router5 and i put also EIGRP and i leave also RIP. Everything is ok. Then i telnet to router4 and i put EIGRP and i leave RIP. After i few min i can not connect to router5 .



sundar.palaniappan Tue, 06/26/2007 - 06:08


What you might want to do is configure a higher admin distance for EIGRP on all routers as suggested by others above, make sure EIGRP is advertising all the networks and remove RIPv2 completely from all the routers. Up to this point your network connectivity should function uninterrupted.

Yes changing the admin distance of EIGRP back to it's default value(s) would cause EIGRP to reconverge and result in a brief disruption. You might want to schedule this change to be performed during a maintenance window and that way it wouldn't affection the production traffic.



moses12315 Tue, 06/26/2007 - 06:30

If i understood correctly you advice first to configure EIGRP with higher AD in all routers. After that remove one by one the RIP from other routers and then change the AD of EIGRP to its default value. During this procedure you mention that i might not have any connectivity problems.


sundar.palaniappan Tue, 06/26/2007 - 06:38

That's correct!!

Make sure all networks that RIPv2 is currently advertising is concurrently advertised by EIGRP before removing RIP. If you do a 'show ip eigrp top' in the routers you should see all those networks that RIP is learning.



moses12315 Wed, 06/27/2007 - 05:11

Hi Sundar

I was talking to a guy today and he told me another solution . He told me to start from the nearest Router first , remove RIP and then install EIGRP. Then go to another Router which is directly connected to the previous etc. He told me clearly no to leave two routing protocols running at the same Router. He also told me to do that during not working hours.



sundar.palaniappan Wed, 06/27/2007 - 05:32


The solution your friend is suggesting will disrupt the production traffic. And yes if you want to do this during a maintenance window then you be should be ok. However, the solution we had suggested to you will not affect the production traffic. Moreover, there's nothing wrong with running two routing protocols at the same time during migration unless the routers are experiencing a severe resource crunch. You don't have to worry about routing loops or other routing issues as you wouldn't be redistributing between the two protocols. Choose the option that you feel comfortable with.

Good Luck!!



royalblues Wed, 06/27/2007 - 05:48

I agree with sundar and i still feel that the you should configure EIGRP with a higher AD and then migrate.

This would require the lease amount of downtime



This Discussion