Changing the IGMP Host−Query Message Interval

As mentioned earlier, the router sends IGMP host−query messages to the network to discover which multicast group is still active. You can modify the message interval setting to accommodate your network’s bandwidth/utilization (the default is 60 seconds):

Router(config−if)# ip igmp query−interval 90

Configuring Multicast Groups

To manually add a multicast group to the switch, enter the following command:

Coriolis> (enable) set cam static 01−00−5e−0c−8−5 2/1−12

Static multicast entry added to CAM table.

This multicast group exists only until you reset the switch. To store the entry in the NVRAM, replace static with permanent:

Coriolis> (enable) set cam permanent 01−00−5e−0c−8−5 2/1−12

Permanent multicast entry added to CAM table.

Removing Multicast Groups

Use the following command to remove a multicast group manually:

Coriolis> (enable) clear cam 01−00−5e−0c−8−5

CAM entry cleared.

This command will remove the entire multicast group from the switch. When you want to remove only one port from the multicast group, you will have to remove the entire group and re−enter the desired port back into the switch.

Configuring Multicast Router Ports

To configure which port the multicast router is connected to, use the following command:

Coriolis> (enable) set multicast router 2/14

Port 2/14 added to multicast router port list.

You can use this command even if you are using IGMP snooping, CGMP, or GMRP.

Displaying Multicast Routers

To verify or display all the multicast router’s ports, use the show multicast router command as shown here:

Coriolis> (enable) show multicast router

CGMP enable

IGMP disable

Port Vlan

151