I thought that the default timers for bgp were 60 and holddown was 180. I may be wrong, but shouldn't a route that falls out of the table be at most put back into the table after 180 seconds (3 min.)?
We tested our failover this weekend, and we shut down our main router to watch our block roll over to our backup router. We lost two packets. I peer with the provider using the same AS on my end (both of my routers are using bgp 1 for instance, and I peer with bgp 2). I'm wondering if this is the reason the failover happened so quickly?
fast-external-fallover tracks the state of the outgoing interface towards the eBGP peer.
If that interface is detected down the session is torned down too without having to wait for hold timer to expire
Hope to help
This behaviour is due to "bgp fast-external-fallover
" enabled by default. This command, suppresseds the timers.
Negate it and retest.
PS: Good post !!