vlan ip igmp


vlan vid ip igmp [auto port-list | blocked port-list | forward port-list]

Used in the VLAN context, specifies how each port should handle IGMP traffic.

Default: auto.


Where a static multicast filter is configured on a port, and an IGMP filter created by this command applies to the same port, the IGMP filter overrides the static multicast filter for any inbound multicast traffic carrying the same multicast address as is configured in the static filter. For more information, see the Management and Configuration Guide for your switch.


Suppose you want to configure IGMP as follows for VLAN 1 on the 100/1000T ports on a module in slot 1:

Ports A1-A2


Filter multicast traffic. Forward IGMP traffic to hosts on these ports that belong to the multicast group for which the traffic is intended. (Also forward any multicast traffic through any of these ports that is connected to a multicast router.)

Ports A3-A4


Forward all multicast traffic through this port.

Ports A5-A6


Drop all multicast traffic received from devices on these ports.

For a description of the default behavior of data-driven switches, see Automatic fast-leave IGMP.

Depending on the privilege level, you could use one of the following commands to configure IGMP on VLAN 1 with the above settings:

switch(config)# vlan 1 ip igmp auto a1,a2 forward a3,a4
blocked a5,a6
switch(vlan-1)# ip igmp auto a1,a2 forward a3,a4
blocked a5,a6

The following command displays the VLAN and per-port configuration resulting from the above commands.

switch show ip igmp vlan 1 config