Enabling Igmp Fast-Leave Processing - HP MSR2003 Configuration Manual

If multiple multicast routers exist on the same subnet, only the IGMP querier sends IGMP queries. When
a non-querier receives an IGMP query, it starts an IGMP other querier present timer. If it receives a new
IGMP query before the timer expires, the non-querier resets the timer. Otherwise, it considers that the
querier has failed and starts a new querier election.
When you configure the IGMP query parameters, follow these guidelines:
To avoid frequent IGMP querier changes, you must set the IGMP other querier present interval
•
greater than the IGMP general query interval.
The configuration of the IGMP other querier present interval takes effect only on the devices that run
•
IGMPv2 and IGMPv3.
To configure the IGMP query parameters:
Step
1. Enter system view.
2. Enter interface view.
3. Set the IGMP general query
interval.
4. Set the IGMP other querier
present timer.

Enabling IGMP fast-leave processing

In some applications, such as ADSL dial-up networking, only one multicast receiver host is attached to an
interface of the IGMP querier. To allow fast response to the leave messages of the host when it switches
frequently from one multicast group to another, you can enable fast-leave processing on the IGMP
querier.
With IGMP fast-leave processing enabled, after receiving an IGMP leave message from a host, the IGMP
querier directly sends a leave notification to the upstream. It does not send IGMP group specific queries
or IGMP group and source specific queries. This reduces leave latency and preserves the network
bandwidth.
The IGMP fast-leave processing configuration is effective only if the device is running IGMPv2 or
IGMPv3.
To enable IGMP fast-leave processing:
Step
1. Enter system view.
2. Enter interface view.
3. Enable IGMP fast-leave
processing.
Command
system-view
interface interface-type
interface-number
igmp query-interval interval
igmp
other-querier-present-interval
interval
Command
system-view
interface interface-type
interface-number
igmp fast-leave [ group-policy
acl-number ]
65
Remarks
N/A
N/A
The default setting is 125 seconds.
By default, the IGMP other querier
present timer is [ IGMP general
query interval ] × [ IGMP
robustness variable ] + [ maximum
response time for IGMP general
queries ] / 2.
Remarks
N/A
N/A
By default, IGMP fast-leave
processing is disabled.