BGP next-hop

Ingo Flaschberger if at
Thu Sep 30 22:01:10 UTC 2010

> i was recently bitten by a cousin of this
> research router getting an ebgp multi-hop full feed from
> (address is relevant)
> it is on a lan with a default gateway 42.666.77.11 (address not
> relevant), so it has
>    ip route  42.666.77.11
> massive flapping results.
> it seems it gets the bgp route for and then can not
> resolve the next hop.  it would not recurse to the default exit.
> of course it was solved by
>    ip route  42.666.77.11
> but i do not really understand in my heart why i needed to do this.

last time severall years ago on cisco I used a route-map to rewrite the 
route-map xx-in permit 10
  set ip next-hop 42.666.77.11
route-map xx-out permit 10
  set ip next-hop x.x.x.x

  neighbor remote-as yyy
  neighbor ebgp-multihop 8
  neighbor route-map xx-in in
  neighbor route-map xx-out out

something like this.

More information about the NANOG mailing list