Unanswered Question
Nov 20th, 2009


We are currently running EIGRP in our LAN and would like to replace with OSPF, but during transition period we still like routing would be dealt by eigrp.

I am thinking to run ospf along with Eigrp on same routed links as eigrp but change AD to 195, and when OSPF is fully populated then disable eigrp and let ospf to take over with its default AD.

Diag attached.

Please can you suggests any other better way to implement this.


I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Jon Marshall Fri, 11/20/2009 - 04:37


I can't read the visio, if possible could you post as .jpg.

EIGRP has an AD of 90 (Internal) and 170 (External). OSPF is 110. So if you only have internal EIGRP routes then you wouldn't need to increase OSPF AD, you could just turn on OSPF and then when all routes have been exchanged remove EIGRP.

If you do have EIGRP 170 routes then yes one way is to increase OSPF AD to above 170. Bear in mind that OSPF is more demanding of router resources than EIGRP so make sure all your routers can run both protocols at the same time.

Without seeing the visio it's difficult to say more. Are you proposing to use OSPF areas or are you simply using one area to replace EIGRP ?


Jon Marshall Fri, 11/20/2009 - 05:02


Thanks for the .jpg.

As all your devices are 6500 switches or 7200 routers then you should have enough horsepower to run both protocols at the same time. Looking at the diagram it looks like you will only be using one OSPF area ?? in which case your plan should work fine.

Out of interest, if you are using only one OSPF area why are you changing from EIGRP to OSPF ?



This Discussion