Redistribution in MP-BGP

[hselak]

Hello,

I have a question regarding the redistribution process in MPLS network on the SAME PE router.

I have PE-CE RIPv2, and in the MPLS is MP-BGPv4. Between MPLS Core and LAN Core is OSPF.

I redistribute RIP to BGP on PE, so I have CE routes in the BGP of my PE router.

If I also redistribute BGP to OSPF on that very same router, will those BGP routes that are redistributed previously from RIP - be again redistributed in the OSPF from BGP?

Thanks,

h.

[attrgautam]

No it would not as the OSPF for the default ipv4 routing table. The PE-CE rip is for the vrf specific routing table. Hence you if you redistribute BGP into OSPF only the ipv4 prefixes will get redistributed not the PE-CE RIP routes learnt over the vrf.

[hselak]

Hello,

Thanks for the response, but I didn't meant in the default OSPF routing table, but in the OSPF vrf User routing table, which is the same vrf as PE-CE link.

So, between PE-CE is RIPv2, vrf User, and between PE-Core is OSPF, vrf User.

thaks,

h.

[attrgautam]

I dont get the topology now. What is this core router ? Are you doing VRF lite or something ?

[hselak]

Hello,

Topology is: CE(1760) - PE(7609) - LAN(6509).

On CE there's RIPv2 with PE in vrf User. On PE there's a redistribution of RIPv2 to BGP.

PE(7609) and LAN (6509) are talking with OSPF in vrf User, so same vrf as PE-CE communication.

If I put redistribute bgp on PE(7609) in OSPF process for vrf User, will those RIPv2 learned routes from CE that are now in BGP be redistributed into OSPF in vrf User and sent to LAN(6509)?

I know that I can redistribute RIP straight to OSPF in vrf User on PE(7609), but I'm wondering will this also do the job.

thanks,

h.

[attrgautam]

OK i get your scenario now. You have 2 PE-CE links one with RIP and the other with OSPF. If iam correct, when you redistribute the BGP into OSPF as it will redistribute the routes learnt in the local router through BGP. IN this scenario, the best routes for the prefixes will be through RIP so until you explicitly redistribute RiP into OSPF , it will not go across.

[hselak]

Hello,

Thanks again for your reply. I'm aware of this what you've described. But this is not an answer I'm looking for.

I don't know if it's possible on the same router (PE-7609) to make a redistribution of CE route 10.5.5.0/24 from RIPv2 (vrf User) to BGP, and then redistribution of this same route 10.5.5.0/24 from BGP to OSPF (vrf User) to another CE.

I don't know if you're able to redistribute routes from BGP to OSPF, which were already redistributed in BGP (previously from RIPv2)?

thanks again,

h.

[attrgautam]

That is exactly what iam saying. It is not possible. Because for the route 10.5.5.0/24 , the route is learnt through rip so when you redistribute bgp into OSPF, this route is not propogated across although it will be in the BGP RIB as a locally originated route (AD=200 and RIP is better with 120). let me know if iam accurate enough this time.

[hselak]

Hello,

So, it's not propagated because it's already in RIP routing table of vrf User?

I just want to add that in this scenario I won't redistribute RIPv2 routes straight to OSPF, in the same vrf User.

If you're right, then only way to redistribute CE routes (RIPv2) on PE to another CE (OSPF) is with using straight redistribute RIP in OSPF process (vrf User) on PE?

Regards,

h.

[attrgautam]

That is right. Only way it will go across is if you redistribute rip into ospf of the 'vrf'. Let me know if it works fine.