EIGRP vs OSPF route selection

[vlad.vlaicu]

Hi guys.

I have a problem with one router with IOS 15.0(1r)M15.

The problem is like this: This router is learning the same route from 2 protocols:

OSPF directly(AD 110) and from EIGRP redistributed (D EX AD 170). So the router is installing in the route table the OSPF route because of the best AD. If the OSPF link is going down then the D EX route is installed in the route table.

Everything is working as expected till now.

The problem is that: When the OSPF link is coming up, the OSPF route is not installed back in the routing table. It remains the same D EX route through EIGRP.

If i issue the clear ip route ROUTE then the OSPF route is installed. Otherwise no.

Any idea ?

Thanks.

[Peter Paluch]

Hello Vlad,

I wonder - do you perform EIGRP-to-OSPF redistribution on this router? That could theoretically conflict with the reinstating of the OSPF route back to the routing table.

Best regards,

Peter

[vlad.vlaicu]

Hello Peter,

Yes, redistribution is performed. Here is the config

in eigrp: redistribute ospf 10 metric 1544 2000 255 1 1500 route-map Voce-To-Eigrp

in ospf: redistribute eigrp 10 subnets route-map Voce_Eigrp_Ospf

route-map Voce-To-Eigrp, permit, sequence 10

  Match clauses:

    ip address prefix-lists: CM-Voce-Qwerty

route-map Voce_Eigrp_Ospf, permit, sequence 10

  Match clauses:

    ip address prefix-lists: Voce_Redistribuire

ip prefix-list CM-Voce-Qwerty: 2 entries

   seq 10 permit 10.7.0.0/24

   seq 15 permit 172.31.1.0/24

ip prefix-list Voce_Redistribuire: 26 entries

   seq 5 permit 10.7.3.64/27

   seq 10 permit 10.7.3.0/27

   seq 15 permit 10.7.1.160/27

   seq 20 permit 10.7.0.0/24

   seq 25 permit 10.7.1.32/27

   seq 30 permit 10.7.1.64/27

   seq 35 permit 10.7.2.32/27

   seq 40 permit 10.7.2.160/27

   seq 45 permit 10.7.2.224/27

   seq 50 permit 10.7.1.0/27

   seq 55 permit 10.7.3.96/27

   seq 60 permit 10.7.1.224/27

   seq 65 permit 10.7.3.192/27

   seq 70 permit 10.7.4.0/27

   seq 75 permit 10.7.3.160/27

   seq 80 permit 10.7.1.192/27

   seq 85 permit 10.7.2.192/27

   seq 90 permit 10.7.4.32/27

   seq 95 permit 10.7.3.128/27

   seq 100 permit 10.7.2.64/27

   seq 105 permit 10.7.1.128/27

   seq 110 permit 10.7.1.96/27

   seq 115 permit 10.7.3.32/27

   seq 120 permit 10.7.2.0/27

   seq 125 permit 10.7.2.96/27

   seq 130 permit 10.7.2.128/27

[Peter Paluch]

Hello Vlad,

Thank you, and I apologize for responding lately. I wonder - the OSPF route you expect to return back - what kind of OSPF route is that? Intra-area, inter-area, external?

Could you perform the show ip route X.X.X.X about this particular route and post the results here both when OSPF-learned and EIGRP-learned?

Also, would it be possible to draw a quick sketch of your network so it is easier to see where do the networks come from and how are they redistributed?

Thank you!

Best regards,

Peter