Igmp Relay; Configuration Guidelines - Lenovo RackSwitch G8264 Application Manual

IGMP Relay

Configuration Guidelines

© Copyright Lenovo 2016
The G8264 can act as an IGMP Relay (or IGMP Proxy) device that relays IGMP
multicast messages and traffic between an Mrouter and end stations. IGMP Relay
allows the G8264 to participate in network multicasts with no configuration of the
various multicast routing protocols, so you can deploy it in the network with
minimal effort.
To an IGMP host connected to the G8264, IGMP Relay appears to be an IGMP
Mrouter. IGMP Relay sends Membership Queries to hosts, which respond by
sending an IGMP response message. A host can also send an unsolicited Join
message to the IGMP Relay.
To an Mrouter, IGMP Relay appears as a host. The Mrouter sends IGMP host
queries to IGMP Relay, and IGMP Relay responds by forwarding IGMP host
reports and unsolicited Join messages from its attached hosts.
IGMP Relay also forwards multicast traffic between the Mrouter and end stations,
similar to IGMP Snooping.
You can configure up to two Mrouters to use with IGMP Relay. One Mrouter acts
as the primary Mrouter, and one is the backup Mrouter. The G8264 uses health
checks to select the primary Mrouter.
Consider the following guidelines when you configure IGMP Relay:
 IGMP Relay is supported in stand‐alone (non‐stacking) mode only.
 IGMP Relay and IGMP Snooping are mutually exclusive—if you enable IGMP
Relay, you must turn off IGMP Snooping/Querier.
Add the upstream Mrouter VLAN to the IGMP Relay list, using the following

command:
RS G8264(config)# ip igmp relay vlan
 If IGMP hosts reside on different VLANs, you must:
Disable IGMP flooding.

RS G8264(config)# vlan <vlan id>
RS G8264(config­vlan)# no flood
Ensure CPU forwarding is enabled; Ensure that multicast data is forwarded

across the VLANs.
RS G8264(config)# vlan <vlan id>
RS G8264(config­vlan)# cpu
<VLAN number>
Chapter 32: Internet Group Management Protocol
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