[j-nsp] eBGP neighbor link failure detection

[Andy Litzinger]

Hi Adam,
  how can i tell if fast external failover is enabled?  I haven't had any
luck finding the command or the Junos documentation.  Same question for
Next-Hop Address Trac(k)ing

thanks!
 -andy


On Sat, Mar 15, 2014 at 5:56 AM, Vitkovský Adam <adam.vitkovsky at swan.sk>wrote:

> You can verify whether the fast external failover is enabled for the
> peer/globally (should be on by default).
> -in that case the 3min hold down timer does not need to expire when the
> link to neighbor fails and the adj-rib-in is flushed immediately.
>
> Also you can verify whether the BGP Next-Hop Address Tracing is enabled
> (should be on by default).
> When enabled BGP does not have to rely on the Scanner process running
> every 60sec to detect that the NH for the prefixes is unreachable.
> With Next-Hop Address Tracing BGP registers NHs with RIB process which
> notifies BGP (delay can be tuned) each time status/metric of the prefix
> corresponding to NH changes.
>
> The above are techniques local to a BGP speaker.
> The other aspect is the propagation of BGP updates throughout the AS.
> To eliminate the propagation delay there are features like local-repair or
> PIC (also local a BGP speaker with a failed link).
>
> adam
>