Configuring L2 Multicast Features 847
Configuring IGMP Snooping on VLANs

Beginning in Privileged EXEC mode, use the following commands to

configure IGMP snooping settings on VLANs.

show mac address-table
multicast [vlan
vlan-id
]
[address
mac-multicast-
address
|
ip-multicast-
address
] [format ip |
mac]]
View entries in the multicast MAC address table. The
show mac address-table multicast command shows only
multicast addresses. Multicast address are shown along
with unicast addresses if the multicast keyword is not used.
Command Purpose
configure Enter global configuration mode.
ip igmp snooping vlan
vlan-id
Enable IGMP snooping on the specified VLAN.
ip igmp snooping vlan
vlan-id
groupmembership-
interval
seconds
Specify the host time-out value for the specified VLAN. If
an IGMP report for a multicast group is not received in
the number of seconds specified by the
seconds
value, this
port is deleted from the VLAN member list of that
multicast group. This command also enables IGMP
snooping on the VLAN.
ip igmp snooping vlan
vlan-id
last-member-
query-interval
seconds
Specify the leave time-out value for the VLAN. If an
IGMP report for a multicast group is not received within
the number of seconds configured with this command
after an IGMP leave was received from a specific interface,
the current port is deleted from the VLAN member list of
that multicast group.
ip igmp snooping vlan
vlan-id
immediate-leave
Enables IGMP snooping immediate-leave mode on the
specified VLAN. Enabling immediate-leave allows the
switch to immediately remove the layer 2 LAN interface
from its forwarding table entry upon receiving an IGMP
leave message for that multicast group without first
sending out MAC-based general queries to the interface.
Command Purpose