Alcatel Carrier Internetworking Solutions 6648 - Manual (Page 228)

Troubleshooting IP Multicast Switching (IPMS) Troubleshooting a Device that Drops Out of an IP Multicast Stream
OmniSwitch Troubleshooting Guide September 2005 page 14-6
You may also have a misconfigured or malfunctioning ip multicast static-querier. In the show ip
multicast queriers command, look for Type of “Static” and check to see if the IP addresses configured
exist and are functioning properly.
Also mentioned was that if a group membership expires it may be because it isn’t on an IP VLAN. This is
probably due to a querying problem. IPMS cannot send IGMP queries on a VLAN that doesn’t have an IP
address, but you can still have another switch in the same VLAN that is configured for IP and is querying.
In this case, things will work because there is still a querier present, even if it is not a local switch.
Remember that queriers are required for the re-solicitation of IGMP clients. Queries are sent every 120
seconds, to which all clients must respond with a membership report.
Also check the flood limits (show interfaces flood rate) to see if the switch is dropping packets due to
them being over the limit:
You want to see Flood only in an IPMS environment. If you see:
-> show interfaces flood rate
Slot/Port peak
rate(Mb/second) Enable
-----------+----------------------+---------------
4/1 47
Flood/multicast
4/2 47 Flood/multicast
4/3 47 Flood/multicast
You will want to set it back to Flood only via:
-> interfaces 4 flood
Note that this is by slot, not by VLAN.