[j-nsp] Proxmox with Multicast & Juniper EX

[Tore Anderson]

* Jeff Meyers

> I am mostly confused why the packets passing the core makes a
> difference at all. For my understanding, igmp-snooping inspects the
> communication and passes multicast traffic to exactly those who shall
> receive it. Why isn't this working? I read that this requires an icmp
> querier. Would it help to configure that querier on one of the
> routers (it's two routers because of VRRP)? Can anyone explain why it
> is working on a local switch but not anymore as soon as a 2nd switch
> is involved in the path?

You'll need a querier in your network if you want IGMP snooping to
work, otherwise the switch will remove the host interfaces from their
subscribed multicast groups after a while. The querier can be one of
the switches (you must configure a l3-interface on the VLAN), it
doesn't have to be the upstream routers.

Other than that there's too little information in your message for me
to say exactly what your problem is. I suggest you play around with the
"show igmp-snooping ... detail" commands on your switches to find out
exactly where the packets gets dropped. Also note that multicast
packets destined for 224.0.0.0/24 are treated differently from other
multicast destinations, so this is important information as well.

https://www.juniper.net/techpubs/en_US/junos12.3/topics/concept/igmp-snooping-ex-series-overview.html

Tore