IBM RackSwitch G8000 Application Manual page 229

© Copyright IBM Corp. 2011
• Ensure multicast traffic reaches the switch to which the host is connected.
Close the application sending the IGMP Reports. Clear the IGMP groups by
flapping (disabling, then re-enabling) the port.
Note: To clear all IGMP groups, use the following command:
RS G8000(config)#
However, this will clear all the IGMP groups and will influence other hosts.
Check if the multicast traffic reaches the switch.
RS G8000# show ip igmp ipmcgrp
If the multicast traffic group is not displayed in the table, check the link state,
VLAN membership, and STP convergence.
• Ensure multicast server is sending all the multicast traffic.
• Ensure no static multicast MACs, static multicast groups, or static multicast
routes are configured.
IGMP queries sent by the Mrouter do not reach the host.
• Ensure the Mrouter is learned on switches B and C.
RS G8000# show ip igmp mrouter
If it is not learned on switch B but is learned on switch C, check the link state of
the trunk group, VLAN membership, and STP convergence.
If it is not learned on any switch, ensure the multicast application is running and
is sending correct IGMP Query packets.
If it is learned on both switches, check the link state, VLAN membership, and
STP port states for the ports connected to the hosts.
IGMP Reports/Leaves sent by the hosts do not reach the Mrouter
• Ensure IGMP Queries sent by the Mrouter reach the hosts.
• Ensure the Mrouter is learned on both switches. Note that the Mrouter may not
be learned on switch B immediately after a trunk group failover/failback.
RS G8000# show ip igmp mrouter
• Ensure the host's multicast application is started and is sending correct IGMP
Reports/Leaves.
RS G8000# show ip igmp groups
RS G8000# show ip igmp counters
A host receives multicast traffic from the incorrect VLAN
• Check port VLAN membership.
• Check IGMP Reports sent by the host.
• Check multicast data sent by the server.
clear ip igmp groups
Chapter 19. Internet Group Management Protocol
227