This feature improves the response time of BGP to adjacency changes by allowing BGP to detect an adjacency change and deactivate the terminated session in between standard BGP scanning intervals. Enabling this feature improves overall BGP convergence.
In an ideal case, after a failure, a BGP router never selects an
invalid path nor delays updates by MRAI. Therefore, routing
convergence time is determined solely by the physical limits of
propagation and processing delay along the best path. Under
these assumptions, we will show that extra downtime and false
uptime are given as follows.
ε(s) = tup(s) + d(s) (1)
f(s) = tdown(s) + d(s) (2)
where d(s) is the propagation delay from S to D, tdown(s)
is the convergence time of the Tdown event, and tup(s) is the
On the internet or if the link flaps too many times, it may not be a feasible option
I haven't really used the neighbor ip-address fall-over feature and hence cannot comment. The above timers are used by us in our internal network and also for PE-CE BGP and it turns out to be fine for us
By default, the BGP hold timer is set to run every 180 seconds in Cisco IOS software. This timer value is set as default to protect the BGP routing process from instability that can be introduced by peering sessions with other routing protocols. BGP routers typically carry large routing tables, so frequent session resets are not desirable. The timer needs to be configured on BGP process where in it will applies to other neighbor as well,
BGP fast peering session deactivation improves BGP convergence and response time to adjacency changes with BGP neighbors. This feature is event driven and configured on a per-neighbor basis. When this feature is enabled, BGP will monitor the peering session with the specified neighbor. Adjacency changes are detected and terminated peering sessions are deactivated in between the default or configured BGP scanning interval.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...