[j-nsp] Strange VRRP problem -- question about restarting process

[Per Granath]

> We have a very odd problem that we've been dealing with for a couple of
> weeks. JTAC is involved but we have not come to a resolution yet. The gist of
> the problem is that we have two MX960s and we're running VRRP on
> multiple interfaces with different Cisco switches in between each pair of
> Juniper interfaces.
> 
> [J] ----- [C]----[C]------ [J]
> 
> The switches are just layer two and we're running VRRP on the routers. The
> problem is that one day, three of the interfaces on the backup router
> suddenly stopped receiving VRRP messages from its peer. JTAC seems to
> think that the Cisco switches just suddenly stopped forwarding VRRP
> messages to the backup router, but that makes zero sense unless some
> bizarre issue just happened to occur on multiple unrelated switches at
> exactly the same moment. I'm still leaning toward a problem on the router.

Did you try disabling IGMP snooping for the VLAN on the switches?