Reference Guide

Internet Group Management Protocol
Internet Group Management Protocol (IGMP) is a communications protocol that hosts use on IPv4 networks to establish multicast group
memberships.
OS10 supports IGMPv1, IGMPv2, and IGMPv3 to manage the multicast group memberships on IPv4 networks.
NOTE: OS10 does not support IGMP snooping in VLT environments.
IGMP snooping
IGMP snooping enables switches to use the information in IGMP packets and generate a forwarding table that associates ports with
multicast groups. When switches receive multicast frames, they forward them to their intended receivers.
OS10 supports IGMP snooping on VLAN interfaces.
Congure IGMP snooping
• Enable IGMP snooping globally with the ip igmp snooping enable command in the CONFIGURATION mode. This command
enables IGMP snooping on all VLAN interfaces.
• (Optional) You can disable IGMP snooping on specic VLAN interfaces using the no ip igmp snooping command in the VLAN
INTERFACE mode.
• In a network, the snooping switch is connected to a multicast Router that sends IGMP queries. On a Layer 2 network that does not
have a multicast router, you can congure the snooping switch to act as querier. Use the ip igmp snooping querier command
in the VLAN INTERFACE mode to send the queries.
• OS10 learns the multicast router interface dynamically based on the interface on which IGMP membership query is received. To assign a
multicast router interface statically, use the ip igmp snooping mrouter interface interface—type command in VLAN
INTERFACE mode.
• (Optional) Congure the IGMP version using the ip igmp version version-number command in the VLAN INTERFACE mode.
• (Optional) The fast leave option allows the IGMP snooping switch to remove an interface from the multicast group immediately on
receiving the leave message. Enable fast leave with the ip igmp snooping fast-leave command in VLAN INTERFACE
mode.
• (Optional) Congure the time interval for sending IGMP general queries with the ip igmp snooping query-interval
query-interval-time command in VLAN INTERFACE mode.
• (Optional) Congure the maximum time for responding to a query advertised in IGMP queries using the ip igmp snooping
query-max-resp-time query-response-time command in VLAN INTERFACE mode.
• (Optional) Congures the time interval between group-specic IGMP query messages with the ip igmp snooping last-
member-query-interval
query-interval-time command in VLAN INTERFACE mode.
IGMP snooping conguration
OS10(config)# ip igmp snooping enable
OS10(config)# interface vlan 100
OS10(conf-if-vl-100)# ip igmp snooping mrouter interface ethernet 1/1/32
OS10(conf-if-vl-100)# ip igmp snooping querier
OS10(conf-if-vl-100)# ip igmp version 3
OS10(conf-if-vl-100)# ip igmp snooping fast-leave
OS10(conf-if-vl-100)# ip igmp snooping query-interval 60
OS10(conf-if-vl-100)# ip igmp snooping query-max-resp-time 10
OS10(conf-if-vl-100)# ip igmp snooping last-member-query-interval 1000
View IGMP snooping information
OS10# show ip igmp snooping groups
Total Number of Groups: 480
IGMP Connected Group Membership
Group Address Interface Mode Expires
225.1.0.0 vlan3531 IGMPv2-Compat 00:01:35
Member-ports :port-channel41,ethernet1/1/51,ethernet1/1/52
384
Layer 3