Brocade Communications Systems Brocate Ethernet Access Switch 6910 User Manual
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Brocade 6910 Ethernet Access Switch Configuration Guide
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Layer 2 IGMP (Snooping and Query)
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If immediate leave is not used, a multicast router (or querier) will send a group-specific query
message when an IGMPv2 group leave message is received. The router/querier stops
forwarding traffic for that group only if no host replies to the query within the specified time out
period. Note that this time out is set to Last Member Query Interval * Robustness Variable
(fixed at 2) as defined in RFC 2236.
If immediate leave is enabled, the switch assumes that only one host is connected to the
interface. Therefore, immediate leave should only be enabled on an interface if it is connected
to only one IGMP-enabled device, either a service host or a neighbor running IGMP snooping.
This attribute is only effective if IGMP snooping is enabled, and IGMPv2 snooping is used.
•
Multicast Router Discovery – MRD is used to discover which interfaces are attached to
multicast routers. (Default: Enabled)
•
General Query Suppression – Suppresses general queries except for ports attached to
downstream multicast hosts. (Default: Disabled)
By default, general query messages are flooded to all ports, except for the multicast router
through which they are received.
If general query suppression is enabled, then these messages are forwarded only to
downstream ports which have joined a multicast service.
•
Proxy Reporting – Enables IGMP Snooping with Proxy Reporting. (Default: Based on global
setting)
When proxy reporting is enabled with this command, the switch performs “IGMP Snooping with
Proxy Reporting” (as defined in DSL Forum TR-101, April 2006), including last leave, and query
suppression.
Last leave sends out a proxy query when the last member leaves a multicast group, and query
suppression means that specific queries are not forwarded from an upstream multicast router
to hosts downstream from this device.
•
Interface Version – Sets the protocol version for compatibility with other devices on the
network. This is the IGMP Version the switch uses to send snooping reports. (Range: 1-3;
Default: 2)
This attribute configures the IGMP report/query version used by IGMP snooping. Versions 1 - 3
are all supported, and versions 2 and 3 are backward compatible, so the switch can operate
with other devices, regardless of the snooping version employed.
•
Query Interval – The interval between sending IGMP proxy general queries. (Range: 2-31744
seconds; Default: 125 seconds)
An IGMP general query message is sent by the switch at the interval specified by this attribute.
When this message is received by downstream hosts, all receivers build an IGMP report for the
multicast groups they have joined.
This command applies when the switch is serving as the querier (
), or as a proxy
host when IGMP snooping proxy reporting is enabled (
•
Query Response Interval – The maximum time the system waits for a response to proxy general
queries. (Range: 10-31740 tenths of a second; Default: 10 seconds)
This command applies when the switch is serving as the querier (
), or as a proxy
host when IGMP snooping proxy reporting is enabled (