I hope this is the right place for multicast and IGMP questions...
The company I am working for provides IPTV services to hotels. The IPTVs are using multicast. The multicast traffic sources are located on a 3750G switch. The switch is also the root for the spanning-tree of the vlan.
There is just one vlan for the multicast so there is only IGMP snooping but no multicast routing (PIM) enabled anywhere. This switch is configured to be the querier for the vlan and no other switches are configured to be the queriers.
Then this switch is connected to two distribution layer switches WS-C4900M (spanning tree correctly blocked one link for this vlan) which in turn connect to other access switches. The multicast traffic recipients (Set Top Boxes or STBs) are located on the access switches (2960).
All other switches except of the 3750 are not managed by us and they are having cabling issues all around. Then the spanning-tree keeps changing (I think). For example on this 3750 switch, when I do "debug ip igmp snooping management" I got these from time to time:
*Mar 17 22:23:38.928: IGMPSN: mgt: Received topology change on vlan 2138
*Mar 17 22:23:38.928: IGMPSN: mgt: Topo-change updates all GCEs with flood portset for in Vlan 2138
*Mar 17 22:23:38.928: IGMPSN: mgt: Updating all GCEs with flood portset for in Vlan 2138
I tried to paste them in the "cisco output interpreter" but it can't find anything. I tried to search GCE and found nothing as well. What is GCE?
I have a STB on port g1/0/15 and when I do "show int g1/0/15 summary" and I see a lot drops on the interface and it's because of the traffic volume is higher than the bandwidth (the link is actually operating on 100Mbps). I did port mirroring and they are all multicast traffic destinated to all multicast channels... However the STB is not joining any of the multicast group at all.
Any suggestion is appreciated! Thank you!