Motorola Netopia 2200 Series User Manual page 212

• IGMP Snooping – enables the Motorola Netopia® Gateway to "listen in" to IGMP traf-
fic. The Gateway discovers multicast group membership for the purpose of restricting
multicast transmissions to only those ports which have requested them. This helps to
reduce overall network traffic from streaming media and other bandwidth-intensive IP
multicast applications.
•
Robustness – a way of indicating how sensitive to lost packets the network is. IGMP
can recover from robustness minus 1 lost IGMP packet. The default value is 2.
•
Query Interval– the amount of time in seconds between IGMP General Query mes-
sages sent by the querier gateway. The default query interval is 125 seconds.
•
Query Response Interval – the maximum amount of time in tenths of a second that
the IGMP router waits to receive a response to a General Query message. The default
query response interval is 10 seconds and must be less than the query interval.
•
Unsolicited Report Interval – the amount of time in seconds between repetitions of a
particular computer's initial report of membership in a group. The default unsolicited
report interval is 10 seconds.
• Querier Version – select a version of the IGMP Querier: version 1, version 2, or version
3. If you know you will be communicating with other hosts that are limited to v1 or v2,
for backward compatibility, select accordingly; otherwise, allow the default v3.
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• 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 off by default, fast leave enables a non-standard expedited leave
mechanism. The querier keeps track of which client is requesting which channel by IP
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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.