Motorola 7000, 3352N, 3342, 2200 manual Igmp Settings, 257

IGMP Settings

NOTE: IGMP Version 3 is supported beginning with Firmware Version 7.7.

See “IGMP (Internet Group Management Protocol)” on page 100 for detailed explanation.

You can set the following options:

•IGMP Snooping – enables the Motorola Netopia® Gateway to “listen in” to IGMP traffic. 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 messages 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 sec- onds and must be less than the query interval.

•Unsolicited Report Interval – the amount of time in seconds between repetitions of a particular com- puter’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.

☛NOTE:

IGMP Querier version is relevant only if the router is configured for IGMP forwarding. 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 member query interval is also the amount of time in seconds between successive Group-Specific Query messages. The default last mem- ber 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 queried 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 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.

•Log Enable – If set to on, all IGMP messages on both the LAN and the WAN will be logged.

•Wireless Multicast to Unicast conversion – Only available if IGMP Snooping is enabled. If set to on, the Gateway replaces the multicast MAC-address with the physical MAC-address of the wireless client. If there is more than one wireless client interested in the same multicast group, the router will revert to multicasting the stream immediately. When one or more wireless clients leave a group, and the router

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