Troubleshooting Igmp Snooping - Lenovo RackSwitch G8264 Application Manual

Troubleshooting IGMP Snooping

508
G8264 Application Guide for ENOS 8.4
This section provides the steps to resolve common IGMP Snooping configuration
issues. The topology described in Figure
Multicast traffic from non‐member groups reaches the host or Mrouter

Check if traffic is unregistered. For unregistered traffic, an IGMP entry is not

displayed in the IGMP groups table.
RS G8264# show ip igmp groups
Ensure IPMC flooding is disabled and CPU is enabled.

RS G8264(config)# vlan <vlan id>
RS G8264(config­vlan)# no flood
RS G8264(config­vlan)# cpu
Check the egress port's VLAN membership. The ports to which the hosts and

Mrouter are connected must be used only for VLAN 2 and VLAN 3.
RS G8264# show vlan
Note: To avoid such a scenario, disable IPMC flooding for all VLANs
enabled on the switches (if this is an acceptable configuration).
Check IGMP Reports on switches B and C for information about the IGMP

groups.
RS G8264# show ip igmp groups
If the 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/MAC address. If the source IP/MAC address is unknown, check the
port statistics to find the ingress port.
RS G8264# show interface port <port id> interface­counters
Ensure no static multicast MACs, static multicast groups, or static Mrouters

are configured.
Ensure IGMP Relay and PIM are not configured.

41 is used as an example.