[c-nsp] Faster iBGP convergance: Tune the timers or use Fast Peering Session Deactivation?

[Sam Stickland]

All,

I'd appreciate any feedback people have on tuning iBGP for faster
convergence, particularly dead peer detection for indirect Loopback to
Loopback peerings.

There seems to be two viable options:

1) Reduce the iBGP timers to 1/3
2) Use fall-over (fast peering session deactivation), with a route-map to
only match /32s so the presence of aggregates or defaults doesn't have an
affect [1]

I heard via some other colleges that Cisco do not recommend FPD due to IGP
instability promoting BGP instability and if we do run into issues with
FPD in production, Cisco will recommend we remove it opposed to a productive
TAC case being endeavoured.

Has anyone got any experience they can share?

Regards,

Sam

[1] Nexthop Tracking has the same limitation, the route never becomes
invalid in the presence of a shorter-match.