4500X VSS WAN connectivity

[eagles-nest]

Hi

I have a dual 4500X VSS setup.  I have one WAN cct on each chassis running BGP.  I have found if I fail the active VSS chassis it takes a significant time for BGP to converge on the standby (now active) chassis.  If I simply fail the each circuit but not the complete chassis the reconvergence via the surviving circuit it acceptable.

Will NSF resolve this problem?  If so do the WAN BGP peers need to configure anything and what failover times should I expect?

As always, thank you for any input.

Stuart.

[Philip D'Ath]

I'm betting if you lower the BGP timers you'll get a better result.

 neighbor a.b.c.d timers 8 24

[eagles-nest]

Thanks for your input Philip.

I already have the timers reduced with timers bgp 1 3 under the bgp process.  I believe this applies to all neighbors.  However, having read into the VSS active chassis failover process I believe the routing neighbors drop as the previous standby chassis takes over control.  I think this is the issue I am seeing.  I think the timers config assists when I lose a neighbor but not when I lose the active chassis.

Although I don't see a specific description of my setup in NSF documentation from what I can gather it may be solution.

Thanks, Stuart.

[Glenn Martin]

I've moved this discussion to the WAN/Routing Forum for greater visibility..