[c-nsp] OSPF on Ring Networks

[Nick Hilliard]

On 14/05/2011 20:00, Christian Meutes wrote:
> Not only customer-link flaps, but also every downtime of any of your
> routers which terminates BGP routes, eg. all edge-routers.

if that happens, then your loopback will disappear in no more than 
dead-time seconds, or possibly earlier if your igp notices that the 
interface carrier drops.  This will cause the ibgp next-hop will be become 
unreachable or else to point by default to the nearest traffic sink on your 
network.   Either way, convergence time won't be hugely different if you 
compare ibgp+loopback igp vs non-infrastructure igp prefix situations, 
because in both cases, all you're doing is updating your fib with an 
igp-induced topology change.

Some time after this, ibgp will notice that the edge device has 
disappeared, at which point the non-infrastructure prefixes will disappear 
from ibgp.

Nick