IP multicast reduces the IP broadcasting data traffic efforts by forwarding the data frames to only those
network devices that expect the designated frames proposing group registration. It is commonly
deployed for triple play services (data, voice, and video), such as a network conference system and
video on demand (VOD).
ASE IPMC, which includes IGMP and MLD protocol support, manages the IP multicast group
registration. Snooping works at the layer 2 MAC level but it handles the IP IGMP (layer 3) control
messages to dedicate a layer 2 MAC forwarding table.
For IPMC snooping, the system needs to be in router mode where the following two roles are defined.
• Querier transmits IPMC queries and is responsible for triggering multicast address determination.
• Non-querier routers not selected as querier in the same broadcast domain, such as a VLAN.
ASE IGMP Defaults
IGMP Snooping Setup Using ICLI
Execute the following steps to set up IGMP snooping using ICLI.
configure terminal
Example
# configure terminal
(config)#
ip igmp { ssm-range <ipv4_mcast> | unknown-flooding }
Example
(config)# ip igmp unknown-flooding
(config)#
interface vlan <vlan_list>
Example 1
(config)# int vlan 1-3,5
(config-if-vlan)#
Example 2
(config)# interface vlan 1
(config-if-vlan)#
ip igmp snooping
Example
(config-if-vlan)# ip igmp snooping
(config-if-vlan)#
ip igmp snooping
{
compatibility { auto | v1 | v2 | v3 } | last-member-query-interval <0-31744>
| priority <0-7> |
querier address <ipv4_ucast> |
querier election |
query-interval <1-31744> |
query-max-response-time <0-31744> | robustness-variable <1-255> | unsolicitedreport-
interval <0-31744>
}
Example
(config-if-vlan)# ip igmp snooping querier election
(config-if-vlan)#
exit
Example
(config-if-vlan)# exit
(config)#
ip igmp snooping
Example
(config)# ip igmp snooping
(config)#
end
Example
(config)# end
#
copy running-config startup-config
Example
# copy running-config startup-config
#