IBM RackSwitch G8000 Application Manual page 237

© Copyright IBM Corp. 2011
• Check IGMP Reports on switches B and C for information about IGMP groups.
RS G8000(config)# show ip igmp groups
If non-member IGMP groups are displayed in the table, close the application that
may be sending the IGMP Reports for these groups.
Identify the traffic source by using a sniffer on the hosts and reading the source
IP address/MAC address. If the source IP address/MAC address is unknown,
check the port statistics to find the ingress port.
RS G8000(config)# show interface port <port id> interface-counters
• Ensure no static multicast MACs and static Mrouters are configured.
Not all multicast traffic reaches the appropriate receivers
Ensure hosts are sending IGMP Reports for all the groups. Check the VLAN on
which the groups are learned.
RS G8000(config)# show ip igmp groups
If some of the groups are not displayed, ensure the multicast application is
running on the host device and the generated IGMP Reports are correct.
• Ensure the 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(config)# 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 the multicast server is sending all the multicast traffic.
• Ensure no static multicast MACs or static multicast routes are configured.
• Ensure PIM is not enabled on the switches.
IGMP Reports/Leaves sent by the hosts do not reach the Mrouter
• Ensure one of the Mrouters is learned on both switches. If not, the IGMP
Reports/Leaves are not forwarded. Note that the Mrouter may not be learned on
switch B immediately after a trunk group failover/failback.
RS G8000(config)# show ip igmp mrouter
• Ensure the host's multicast application is started and is sending correct IGMP
Reports/Leaves.
RS G8000(config)# show ip igmp groups
RS G8000(config)# show ip igmp counters
clear ip igmp groups
Chapter 19. Internet Group Management Protocol
235