User guide

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• Querier Version – select a version of the IGMP Querier: version 1 or version 2. If you
know you will be communicating with other hosts that are limited to v1, for backward
compatibility, select v1; otherwise, allow the default v2.
☛ NOTE:
IGMP Querier version is relevant only if the router is configured for IGMP for-
warding. If any IGMP v1 routers are present on the subnet, the querier must
use IGMP v1. The use of IGMP v1 must be administratively configured, since
there is no reliable way of dynamically determining whether IGMP v1 routers
are present on a network. IGMP forwarding is enabled per IP Profile and WAN
Connection Profile.
• Last Member Query Interval – the amount of time in tenths of a second that the IGMP
gateway waits to receive a response to a Group-Specific Query message. The last mem-
ber query interval is also the amount of time in seconds between successive Group-
Specific Query messages. The default last member query interval is 1 second (10 deci-
seconds).
• Last Member Query Count – the number of Group-Specific Query messages sent
before the gateway assumes that there are no members of the host group being que-
ried on this interface. The default last member query count is 2.
• Fast Leave – set to on by default, fast leave enables a non-standard expedited leave
mechanism. The querier keeps track of which client is requesting which channel by IP
address. When a leave message is received, the querier can check its internal table to
see if there are any more clients on this group. If there are none, it immediately sends
an IGMP leave message to the upstream querier.
set igmp snooping [ off | on ]
Enables IGMP Snooping.
set igmp robustness value
Sets IGMP robustness range: from 2 – 255. The default is 2.
set igmp query-intvl value
Sets the query-interval range: from 10 seconds – 600 seconds, The default is 125 sec-
onds.