BGP nexthop-self vs. EIGRP redistribution
jbates at brightok.net
Mon Mar 16 12:06:06 CDT 2009
phil at mindfury.net wrote:
> ...which is better?
Neither (both) is better, depending on the scenario. This is especially
true when mixing in MPLS and other features.
> My question is, which is the correct method of implementing this? Should
> we be redistributing static and connected routes on our borders into IGP,
> and not using next-hop-self? Or should we not redistribute and use
next-hop-self seems to remain more stable overall. In some scenarios I
believe it is even required (just as not using it is required in other
scenarios). For your deployment, I'd say you are open to choose either,
and next-hop-self would be the more stable of the two. The largest issue
with NOT using next-hop-self that I have seen is the effect it has when
that IGP route for the next hop disappears. BGP tends to be more
graceful about removing routes via iBGP then handling routes locally
when they are suddenly unreachable via IGP.
Another benefit of next-hop-self is the fact that the IGP doesn't have
to be overly enlarged when you have a large network (injecting hundreds
or thousands of links into IGP). With OSPF/ISIS in a flat (single area)
topology utilizing MPLS across the core, you would prefer stability in
the link state database. Each edge network you place in IGP increases
the chances of a database change, and in critical outages, they increase
the number of changes that must be made.
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