C
ONFIGURING
THE
S
WITCH
3-200
multicast router), indicate the VLAN that will propagate the multicast
service, specify the multicast IP address, and click Add. After you have
completed adding ports to the member list, click Apply.
CLI – This example assigns a multicast address to VLAN 1, and then
displays all the known multicast services supported on VLAN 1.
Layer 3 IGMP (Query used with Multicast Routing)
IGMP Snooping – IGMP Snooping is a Layer 2 function (pag e 3-193) that
can be used to provide multicast filtering when no other switches in the
network support multicast routing. (Note that IGMP Snooping can only
be globally enabled.)
IGMP Query – Multicast query is used to poll each known multicast group
for activemembers, and dynamically configure the switch ports which
need to forward multicast traffic. Although the implementation differs
slightly, IGMP Query is used in conjunction with both Layer 2 IGMP
Snooping and multicast routing. Note that when using IGMP Snooping,
multicast query is automatically enabled. (See “Configuring IGMP
Snooping and Query Parameters” on page 3-193.)
Console(config)#ip igmp snooping vlan 1 static 224.1.1.12
ethernet 1/123-96
Console(config)#exit
Console#show mac-address-table multicast vlan 13-99
VLAN M'cast IP addr. Member ports Type
---- --------------- ------------ -------
1 224.1.1.12 Eth1/12 USER
1 224.1.2.3 Eth1/12 IGMP
Console#