Extreme Networks ExtremeWare 7.7, Command Reference Manual

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configure igmp snooping timer
ExtremeWare 7.7 Command Reference Guide 2027
configure igmp snooping timer
configure igmp snooping timer <router timeout> <host timeout>
Description
Configures the IGMP snooping timers.
Syntax Description
Default
• router timeout default—260 seconds
• host timeout default—260 seconds
Usage Guidelines
Timers should be set to approximately 2.5 times the router query interval in use on the network. Specify
the following:
• router timeout—The interval, in seconds, between the last time the router was discovered and the
current time. The range is 10 to 2,147,483,647 seconds (68 years). The default setting is 260 seconds.
• host timeout—The interval, in seconds, between the last IGMP group report message from the host
and the current time. The range is 10 to 2,147,483,647 seconds (68 years). The default setting is 260
seconds.
IGMP snooping is a layer 2 function of the switch. It does not require multicast routing to be enabled.
The feature reduces the flooding of IP multicast traffic. IGMP snooping optimizes the usage of network
bandwidth and prevents multicast traffic from being flooded to parts of the network that do not need it.
The switch does not reduce any IP multicast traffic in the local multicast domain (224.0.0.x).
IGMP snooping is enabled by default on the switch. If you are using multicast routing, IGMP snooping
can be enabled or disabled (in versions of ExtremeWare previous to 7.0.0, IGMP snooping must have
been enabled for multicast routing). If IGMP snooping is disabled, all IGMP and IP multicast traffic
floods within a given VLAN. IGMP snooping expects at least one device on every VLAN to periodically
generate IGMP query messages. Without an IGMP querier, the switch eventually stops forwarding IP
multicast packets to any port, because the IGMP snooping entries will time out, based on the value
specified in
host timeout
. An optional optimization for IGMP snooping is the strict recognition of
routers only if the remote devices are running a multicast protocol.
Example
The following command configures the IGMP snooping timers:
configure igmp snooping timer 600 600
router timeout Specifies the time in seconds between router discovery. Default is 260
seconds.
host timeout Specifies the time in seconds between host reports. Default is 260 seconds.