EIGRP to OSPF

adnan.dhl · ‎03-25-2008

How to convert live network EIGRP to ospf?

royalblues · ‎03-25-2008

You can run both OSPF and EIGRP at the same time . Let OSPF build its topology table.

Routing should not get affected since the default administrative distance of OSPF is greater than EIGRP and the router would continue to use EIGRP for forwarding packets.

All you need to look out is for the EIGRP external routes which by default would have an AD of 170 and the router might choose OSPF instead.

Later on you can change the AD of EIGRP to be greater than 110 and migrate

HTH

Narayan

Istvan_Rabai · ‎03-25-2008

Hi Adnan,

I basically agree with Narayan.

Just one addition to his post:

If you have a somewhat larger network, then you'd better plan for some ospf hierarchy by using ospf areas.

In eigrp there is no concept of areas, this is why the conversion in this case may take some careful planning.

This hierarchical design may be needed to allow route summarization, thereby faster convergence of the ospf dijkstra algorithm, and a better use of router resources.

If you post your network topology, probably we will be able to help you with some more specific hints.

Cheers:

Istvan