[j-nsp] NSR interfering with OSPF?

[Stefan Fouant]

> -----Original Message-----
> From: juniper-nsp-bounces at puck.nether.net [mailto:juniper-nsp-
> bounces at puck.nether.net] On Behalf Of Justin M. Streiner
> Sent: Friday, February 05, 2010 11:42 AM
> To: juniper-nsp at puck.nether.net
> Subject: [j-nsp] NSR interfering with OSPF?
> 
> I'm running into an issue on an M10i running JUNOS 8.5R4.3 where when I
> enable Nonstop Active Routing, it seems to interfere with OSPF's
> ability
> to flood link-state updates to its neighbors.  When I enabled NSR on
> this
> router, I started getting alarms in my management system that it was
> re-transmitting link-state updates, and when I disabled NSR, the alerts
> went away.  It appears that when this happens, the router will revert
> to
> sending link-state updates via unicast to maintain the integrity of the
> link-state database, though it still issues alerts when it does so.
> 
> I have a case open with JTAC, but I haven't gotten much traction on it
> yet.  Has anyone else here run into this or something similar?

I'm willing to bet that has something to do with kernel replication of the
LSAs to the backup RE.  The backup RE snoops the LSAs and builds its own
Link State Database (this is done to avoid fate sharing in the event the
primary RE has a bug, we don't want to replicate state from the primary RE).

Are you just seeing alerts, or is it actually breaking something?

Stefan Fouant, CISSP, JNCIE-M/T
www.shortestpathfirst.net
GPG Key ID: 0xB5E3803D