Igmp Snooping Configuration At The Bridge Domain Level; Igmp Minimum Version; System Ip Address; Group Membership Interval, Robustness Variable, And Query Interval - Cisco ASR 9000 Series Configuration Manual

Implementing Layer-2 Multicast with IGMP Snooping

IGMP Snooping Configuration at the Bridge Domain Level

IGMP Minimum Version

The minimum-version command determines which IGMP versions are supported by IGMP snooping in the
bridge domain:
• When minimum-version is 2, IGMP snooping intercepts IGMPv2 and IGMPv3 messages. This is the
• When minimum-version is 3, IGMP snooping intercepts only IGMPv3 messages and drops all IGMPv2
IGMPv1 is not supported. The scope for this command is the bridge domain. The command is ignored in a
profile attached to a port.

System IP Address

The system-ip-address command configures an IP address for IGMP snooping use. If not explicitly configured,
the default address is 0.0.0.0. The default is adequate except in the following circumstances:
• If you are configuring an internal querier. The internal querier cannot use 0.0.0.0.
• If the bridge needs to communicate with an IGMP router that does not accept the 0.0.0.0 address.
The IGMP snooping system IP address is used in the following ways:
• The internal-querier sends queries from the system IP address. An address other than the default 0.0.0.0
• IGMPv3 sends proxy reports from the systemIP address. The default address 0.0.0.0 is preferred but
• In response to topology change notifications (TCNs) in the bridge domain, IGMP snooping sends

Group Membership Interval, Robustness Variable, and Query Interval

The group membership interval (GMI) controls when IGMP snooping expires stale group membership states.
The show igmp snooping group command shows groups with an expiry time of 0 until that stale state is
cleaned up following the next query interval.
The GMI is calculated as:
GMI = (robustness-variable * query-interval) + maximum-response-time
where:
• maximum-response-time (MRT) is the amount of time during which receivers are required to report
• robustness-variable is an integer used to influence the calculated GMI.
default value.
messages.
must be configured.
may not be acceptable to some IGMP routers.
global-leaves from the system IP address. The default address 0.0.0.0 is preferred but may not be
acceptable to some IGMP routers.
their membership state.
Cisco ASR 9000 Series Aggregation Services Router Multicast Configuration Guide, Release 6.0.x
IGMP Snooping Configuration at the Bridge Domain Level
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