3Com Switch 8800 Advanced Software V5 Configuration Guide

Troubleshooting IGMP Snooping Configuration 561
Solution
1 Use the display acl command to check the configured ACL rule. Make sure that
the ACL rule conforms to the multicast group policy to be implemented.
2 Use the display this command in IGMP Snooping view or in the corresponding
interface view to check whether the correct multicast group policy has been
applied. If not, use the group-policy or igmp-snooping group-policy command
to apply the correct multicast group policy.
3 Use the display current-configuration command to check whether the function
of dropping unknown multicast data is enabled. If not, use the drop-unknown
command to enable the function of dropping unknown multicast data.
4 Use the display igmp-snooping group command to check whether any port has
been configured as a static member port of any multicast group. If so, check
whether this configuration conflicts with the configured multicast group policy. If
any conflict exists, remove the port as a static member of the multicast group.