Brocade Communications Systems IPMC5000PEF manual Configuring report control

Configuring report control

Configuring report control

A device in passive mode forwards reports and leave messages from clients to the upstream router ports that are receiving queries.

You can configure report control to rate-limit report forwarding within the same group to no more than once every 10 seconds. This rate-limiting does not apply to the first report answering a group-specific query.

NOTE

This feature applies to IGMP V2 only. The leave messages are not rate limited.

IGMP V2 membership reports of the same group from different clients are considered to be the same and are rate-limited.

Use the ip multicast report-controlcommand to alleviate report storms from many clients answering the upstream router query.

device(config)#ip multicast report-control

Syntax: [no] ip multicast-report-control

The original command, ip igmp-report-control , has been renamed to ip multicast report-control . The original command is still accepted; however, it is renamed when you configure a show configuration command.

Modifying the wait time before stopping traffic when receiving a leave message

You can define the wait time before stopping traffic to a port when a leave message is received. The device sends group-specific queries once per second to ask if any client in the same port still needs this group. Due to internal timer granularity, the actual wait time is between n and (n+1) seconds (n is the configured value).

device(config)#ip multicast leave-wait-time 1

Syntax: [no] ip multicast leave-wait-timenum

num is the number of seconds from 1 through 5. The default is 2 seconds.

Modifying the multicast cache age time

You can set the time for an mcache to age out when it does not receive traffic. The traffic is hardware switched. One minute before aging out an mcache, the device mirrors a packet of this mcache to CPU to reset the age. If no data traffic arrives within one minute, this mcache is deleted. A lower value quickly removes resources consumed by idle streams, but it mirrors packets to CPU often. A higher value is recommended only data streams are continually arriving.

device(config)#ip multicast mcache-age 180

Syntax: [no] ip multicast mcache-age num

num is the number of seconds from 60 through 3600. The default is 60 seconds.

FastIron Ethernet Switch IP Multicast Configuration Guide	23
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