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EIGRP to OSPF Redistribution

I have a problem with a network (simulated in Cisco packet Tracer) redistributing eigrp to ospf

Following is the network:

Router0, 1, 2, 3 run EIGRP on the links to each other and OSPF on the links southbound. They have redistribution from OSPF to EIGRP and vice versa.

Everything works fine, until I break the Link with the red cross. I would expect, that the Routers would not see anymore the route to 195.195.195.0.

However all routers do have a route to the yellow network. E.g. Router9 would see the yellow route via Router 4,5,6 (with the link ok Router9 has a route via Router6 only.

I assume, the I have to configure something on the redistribution level (metric, etc.)

Please advise

3 REPLIES
VIP Purple

Hi

Hi

Could you share your packet tracer file with config?

Could you share output of sh ip route for 195 subnet when the link is disconnected? While disconnected, do a sh ip ospf database.

When we solved that issue well move to your next issue you described with the link connected back.

Thanks

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Thanks
Francesco
PS: Please don't forget to rate and select as validated answer if this answered your question
Super Bronze

Whenever using Packet Tracer,

Whenever using Packet Tracer, you need to realize the Packet Tracker might be doing something incorrectly.  That may not be the case here, but something to keep in mind.

That noted, mutual redistribution can easily be done incorrectly, so it's also possible, you have a convergence issue where the route stays in the two routing protocols because both keep getting stale information from the other.  Your note about R9 seeing a shift from R6 alone to R4, R5 and R6 probably means in the first instance R9 sees the route as an internal OSPF route, and in the latter instance R9 sees the route as an external route.

What you might check, insure when EIGRP accepts routes from OSPF it doesn't advertise them back to OSPF and likewise when OSPF accepts routes from EIGRP it doesn't advertise them back to EIGRP.  Using a route tag is often an easy method to identify routes and preclude giving them back to the routing protocol that they were initially accepted from

BTW, another limitation of Packet Tracer, sometimes some IOS commands are not supported.

VIP Purple

Hello

Hello

If you haven't done this already, I would suggest to tag you redistribution so the redistributed routes dontcome back at you.

route-map eigp-in-ospf deny 10
deny 170
route-map eigp-in-ospf permit 99
set tag 110

router ospf x
redistribute eigrp xx subnets route-map eigp-in-ospf


route-map ospf-in-eigrp deny 10
deny 110
route-map ospf-in-eigrp permit 99
set tag 170

router eigrp x
redistribute ospf x metric 1 1 1 1 route-map ospf-in-eigrp


res
Paul

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