NXOS Mutual redistribution between EIGRP/OSPF

[jon.divita@gmail.com]

Good evening!  I'm working on mutual redistribution on a pair of 7Ks OSPF<->EIGRP.  The situation is my OSPF and EIGRP domains were originally built with no real design.  Previous admins would just pick random ranges, so summarization is difficult to build prefix lists.   I understand the need for route-maps to prevent loops from redistribution.  So, is my logic correct that I can perform the following on each of my ASBR's?  I'm trying to tag all routes in EIGRP with 90 and OSPF with 110...then denying on the return by matching the tags. 

This appears to work in a virtual environment, but it's non NXOS, so wanted some input.

Or do I have to build large prefix lists to accomplish and have to remember to add any new prefixes?

EIGRP to OSPF RM:

route-map eigrp2ospf deny 10
match tag 110
!
route-map eigrp2ospf permit 20
set tag 90

OSPF to EIGRP RM:
route-map ospf2eigrp deny 10
match tag 90
!
route-map ospf2eigrp permit 20
set tag 110

Thank you!

[Francesco Molino]

Hi

What's your configuration? 

when you do show ip route, do you see all tags?

[jon.divita@gmail.com]

I applied the above configuration to my 2 ASBRs and for the most part, all looks good. However, any EIGRP External routes (AD170) turn into OSPF routes and then a loop is resulting.  I assume due to OSPF having an AD of 110.  But, I cannot reproduce this behavior in my home lab.  

I included a drawing in the main message.

[jon.divita@gmail.com]

So, this really isn't an issue after all.  I wasn't looking at both ASBRs to see how the routing tables looked.  My External EIGRP route was being injected into OSPF.  The neighboring ASBR sees my EIGRP route as an OSPF route because of the redistribution and the lower AD wins 110 vs 170.

[Francesco Molino]

Usually you would tag routes before and leverage these tags when redistributing to different protocols.

Let me do a quick lab and shows you what the config looks like.

Do you have some configs to share then I can fit with your configs.