[c-nsp] About bgp fast-external-fallover

[Oliver Boehmer (oboehmer)]

Christian Meutes <> wrote on Friday, March 07, 2008 9:10 AM:

> Hi,
> 
> --On Freitag, 7. März 2008 12:48 +0900 Hiromasa Sekiguchi
> <hiromasa.sekiguchi at ctc-g.co.jp> wrote:
> 
>> The cisco products have "bgp fast-external-fallover" function.
>> It is available on only eBGP, isn't it?
>> 
>> We'd like to do same behabior like it on iBGP.
>> So, is there any solutions?
> 
> Many new releases have something similar for iBGP learned prefixes
> which is enabled by default. Check for 'BGP Support for Next-Hop
> Address Tracking'. 

Right. And there is actually a feature "Fast Session Deactivation" which builds on address tracking which takes down the session when the next-hop goes away. Hoever, this is usually a bad idea for iBGP, it's better letting "regular" next-hop tracking invalidate the paths rather than taking down the whole session.

	oli