Migrating from EIGRP to OSPF

[bmisenor]

Hello All,

I have a customer who is utilizing both EIGRP and OSPF routing protocols in their network. Their network falls under the AS of my company and we would like to move tem to a pure OSPF routing environment, with their own area id. Their network has a c7200 that is their gateway to our network and it utilizes purely OSPF. That c7200 is connected to a switched network of three uBR7223 routers, one of which utilizes both OSPF and EIGRP, and two of which utilize just EIGRP.

My question / concern is are there migration strategies / plans documented and available that will allow me to plan for a successfull migration to pure OSPF routing environment without breaking routing? For example, do I enable OSPF first on all routers and then disable EIGRP? I am looking for the best way to stategically enable OSPF routing without breaking routing. How can I do this?

[thisisshanky]

You should be enabling OSPF first, on all routers, so that routes get converged via OSPF. Still routing wouldnt break, 7223 (which does redistribution between EIGRp and OSPF) will still keep the EIGRP routes, as administrative distance for EIGRP is 90 while ospf is 110. Once OSPF converges ( all OSPF DB on all routers are synchronized), you can safely remove EIGRP.