[c-nsp] igmp snooping inside 802.1q trunks

[Vladimir Ivashchenko]

Hi List,

I have a problem with multicast on 802.1q trunk ports. We have a network
consisting of Catalyst 3560 with multicast source + a number of Catalyst
6500 where receivers are placed. Multicast is flat on a single VLAN (no
routers) and IGMP snooping is configured on all the switches.

The problem is that 6500 seems to unconditionally forward all multicast
traffic to all trunk ports even if there are no receivers there. E.g.
"show mac-address-table multicast" does not show any entries for that
port, however it still receives all multicast traffic.

Any ideas?

-- 
Best Regards,
Vladimir Ivashchenko
Chief Technology Officer
Thunderworx Cyprus - www.thunderworx.com