Planet Networking & Communication SGS-5240 Series User Manual page 110

◆Version Exclusive – Discards any received IGMP messages (except for multicast protocol packets) which use a version
different to that currently configured by the IGMP Version attribute. (Default: Disabled)
If version exclusive is disabled on a VLAN, then this setting is based on the global setting configured on the Multicast > IGMP
◆Immediate Leave Status – Immediately deletes a member port of a multicast service if a leave packet is received at that port
Snooping > General page. If it is enabled on a VLAN, then this setting takes precedence over the global setting.
and immediate leave is enabled for the parent VLAN.
(Default: Disabled)
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
◆Multicast Router Discovery – MRD is used to discover which interfaces are attached to multicast routers.
running IGMP snooping. This attribute is only effective if IGMP snooping is enabled, and IGMPv2 snooping is used.
◆General Query Suppression – Suppresses general queries except for ports attached to downstream multicast hosts.
(Default: Enabled)
(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
◆Proxy Reporting – Enables IGMP Snooping with Proxy Reporting.
multicast service.
(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: 10-31744 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 .
◆Last Member Query Interval – The interval to wait for a response to a group-specific or group-and-source-specific query
message.
(Range: 1-31740 tenths of a second in multiples of 10; Default: 1 second)
When a multicast host leaves a group, it sends an IGMP leave message. When the leave message is received by the switch, it
checks to see if this host is the last to leave the group by sending out an IGMP group specific or group-and-source-specific
query message, and starts a timer. If no reports are received before the timer expires, the group record is deleted, and a report
User's Manual of SGS-5240 Series Managed Switch
110