[c-nsp] Faster BGP Failover

[Oliver Boehmer (oboehmer)]

> On Thu, 2011-10-13 at 23:35 +0800, Mark Tinka wrote:
> > On Thursday, October 13, 2011 10:27:00 PM Kevin Hodle wrote:
> > > ip routing protocol purge interface
> >
> > A knob that's a must on all our IOS routing devices.
> 
> Are there no downsides to this at all? Does that depend on platform?
The
> "Usage Guidelines" for IOS 12.2 Routing Protocols do not mention any,
> but there must be a reason why it's not default. Or isn't there?

in most cases we rather not change defaults (yes, I know, there have
been too many cases where we did, incl. without notice), and in some
smaller-scaled untuned OSPF network scenarios the RIB purge actually has
some benefits (could take up a floating static ~5 secs quicker, for
example in a spoke node with a backup). so changing the default has some
implications.
I agree that it should be default these days (it is in XR & NX-OS), but
so should be lower spf/lsa-throttle timers.

	oli