[c-nsp] iBGP fall-over with 6500/SXI and summary routes

[Phil Mayers]

All,

We run a bunch of 6500s on 12.2(33)SXI, and I want to make our iBGP 
failover faster. Unfortunately, this release of the software seems to 
lack the "route-map" option to "neighbor fall-over".

This is a problem, because we have a covering static to Null0 for our 
loopback range. The "default" route isn't an issue because it's in BGP 
and thus won't be considered for resolving an iBGP peer, but the 
covering static is a problem, because it's not a BGP route on the 
router(s) that originate it:

#sh ip route 19x.x.x.11
Routing entry for 19x.x.x.0/23, supernet
   Known via "static", distance 240, metric 0 (connected)
   Redistributing via bgp 6xxxx
   Advertised by bgp 6xxxx route-map RedistBGP
   Routing Descriptor Blocks:
   * directly connected, via Null0
       Route metric is 0, traffic share count is 1

...and on these routers, fall-over doesn't kick in because it's able to 
find a "valid" less-specific.

I do need the summary route, to advertise to our upstream.

In the absence of the "route-map" argument to "fall-over" to limit it to 
matching /32 (why oh why isn't that the default for iBGP!) does anyone 
have any ideas? I could presumably originate the covering route from a 
separate router dedicated for the purpose, but it seems a bit of a waste 
of hardware!

One thing I have noticed: if I let the router(s) originate their 
loopbacks via both OSPF and BGP, when the OSPF goes away the BGP version 
of the loopback route kicks in, and RT: complains about recursion and 
drops the connection immediately, but that seems like a hack and that it 
might not be reliable.