Owner manual

3-40 Firmware User Guide
• IGMP Snooping – toggling this option to On enables the Netopia Router to “listen in” to IGMP traffic. The
Router 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(s) – the amount of time in seconds between IGMP General Query messages sent by the
querier router. The default query interval is 125 seconds.
• Query Response Interval (deci-sec) – 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(s) – 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.
• IGMP Querier Version – select a version of the IGMP Querier from the pop-up menu: v1, v2 or v3. 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.
If you have upgraded from earlier firmware versions, and had previously selected v2, v3 will be the new
default.
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.
See “Multicast Forwarding” on page 7-33 for more information.
If you chose IGMP Querier Version v2 or v3, select V2/V3 Settings, and press Return.