Redistribute EIGRP into BGP or visa versa - which is best?

patrick.hurley · ‎11-29-2007

I have a BGP MPLS cloud. My customer is running EIGRP, they have 3 paths between two sites, on his CE routers but must also run BGP for MPLS cloud access. I assume its better to redistribute EIGRP into BGP than visa versa. Comments?

s.arunkumar · ‎11-29-2007

It depends on the number of routes in the BGP.Normaly it is not a good paractice to redistribute a bgp into igp as the number of routes in bgp would be very large that the igp process could handle it.

But in mpls vpn the bgp can be redistributed as the number of routes would be less in the vrf instance of the customer.

lets hear for experts more abt it :)

patrick.hurley · ‎11-29-2007

There aren't many BGP routes in MPLS backbones because its based upon the customer VRF table not on the size of the Internet routing tables. I am wondering if there are other technical reasons. I am thinking that redistributing EIGRP into BGP is the way to go.

Jon Marshall · ‎11-30-2007

Hi Patrick

We use EIGRP and then BGP to peer with our MPLS provider. A lot depends on how much you can summarise the internal EIGRP network at the customer sites.

We redistribute BGP into EIGRP so any routes coming from other sites via the MPLS cloud get distributed into the local routing tables. We don't advertise EIGRP into BGP, we just use summary network statements under BGP. That way any change in a link within the internal network does not affect a BGP advertisement update.

Whichever way you choose to go i would suggest only advertising summary routes, if you can, into BGP.

HTH

Jon

paul.matthews · ‎11-30-2007

I dislike redistribution, but accept that sometimes it is the most practical solution.

If I could, I would use network statements to export the eigrp routing info (summarised where possible) and generate a default route in eigrp.

P.