rip2 to eigrp redistribution

[djnelson]

When re-distributing from rip2 to eigrp (and reverse)are the incoming rip routes checked first against the rip database to verify that they are better than what's in the database before they are redistributed into eigrp. I had a nasty feedback loop today and woud like to know how the rip routes are processed. Thanks

[zaziz]

in mutual redistribution cases feedback loops can occur very easily. Only those RIP routes are

redistributed in EIGRP which are installed in the routing table. Other routes should not be redistributed from RIP database which are not in the routing table.

I am sure you are aware that using tags or route-map may help prevent such loops

Zaheer

[djnelson]

All my eigrp routes are in the RIP database with a metric of 10 (default metric 10). Both redistribution points use the same default metrics. EIGRP routes coming through the rip network back to the other redistribution point to the EIGRP network should have a hop count greater than 10 and not cause a database update and therefore not get re-distributed back with the eigrp default metrics? I never found a good explanation on CCO. I am planning on using distribution-lists to protect the networks from each other.

[ruwhite]

Redistribution is always done from the routing table; when you are redistributing, you need to use distribute lists or the distance command in some way to block routing loops. You could set your default metric on the routes coming in to RIP so it's really high--higher than the metrics you are learning the native RIP routes with.

There are a good number of methods to break this routing loop, but don't count on the routing protocols to do it automagically.

Russ

[djnelson]

Russ,

Thanks. I was hoping that the routes would be checked by RIP before they were re-distributed in eigrp. I am putting in distribute-lists to manage the routes. What is the RIP database used for? I would think it would be logical not magical to check against the rip database before the routing table (using the default eigrp metric). If I do a sho rip database I see all the eigrp routes with hop count of 10. Any update incoming from RIP would have a higher hop count for these eigrp routes.

Thanks..

Dave