Use the Multicast > IGMP Snooping > Interface (Configure VLAN) page to configure IGMP snooping attributes for a VLAN.
ID of configured VLANs.
When enabled, the switch will monitor network traffic on the indicated VLAN interface to determine which hosts want to receive multicast traffic. This is referred to as IGMP Snooping. (Default: Disabled)
When IGMP snooping is enabled globally, the per VLAN interface settings for IGMP snooping take precedence.
When IGMP snooping is disabled globally, snooping can still be configured per VLAN interface, but the interface settings will not take effect until snooping is re-enabled globally.
Discards any received IGMP messages (except for multicast protocol packets) which use a version different to that currently configured by the IGMP Version attribute. (Options: Enabled, Using Global Status; Default: Using Global Status)
If version exclusive is disabled on a VLAN, then this setting is based on the global setting configured on the Multicast > IGMP Snooping > General page. If it is enabled on a VLAN, then this setting takes precedence over the global setting.
Immediately deletes a member port of a multicast service if a leave packet is received at that port 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 running IGMP snooping.
This attribute is only effective if IGMP snooping is enabled, and IGMPv2 or IGMPv3 snooping is used.
If immediate leave is enabled, the following options are provided:
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 running IGMP snooping.
The switch will not send out a group-specific query when an IGMPv2/v3 leave message is received. But will check if there are other hosts joining the multicast group. Only when all hosts on that port leave the group will the member port be deleted.
MRD is used to discover which interfaces are attached to multicast routers. (Default: Disabled)
Suppresses general queries except for ports attached to downstream multicast hosts. (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 multicast service.
Enables IGMP Snooping with Proxy Reporting. (Options: Enabled, Disabled, Using Global Status; Default: Using Global Status)
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.
Rules Used for Proxy Reporting
When IGMP Proxy Reporting is disabled, the switch will use a null IP address for the source of IGMP query and report messages unless a proxy query address has been set.
When IGMP Proxy Reporting is enabled, the source address is based on the following criteria:
If a proxy query address is configured, the switch will use that address as the source IP address in general and group-specific query messages sent to downstream hosts, and in report and leave messages sent upstream from the multicast router port.
If a proxy query address is not configured, the switch will use the VLAN's IP address as the IP source address in general and group-specific query messages sent downstream, and use the source address of the last IGMP message received from a downstream host in report and leave messages sent upstream from the multicast router port.
Sets the protocol version for compatibility with other devices on the network. This is the IGMP Version the switch uses to send snooping reports. (Options: 1-3, Using Global Version; Default: Using Global Version)
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.
The interval between sending IGMP 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 attribute applies when the switch is serving as the querier, or as a proxy host when IGMP snooping proxy reporting is enabled.
The maximum time the system waits for a response to general queries. (Range: 10-31740 tenths of a second in multiples of 10; Default: 10 seconds)
This attribute applies when the switch is serving as the querier, or as a proxy host when IGMP snooping proxy reporting is enabled.
The interval to wait for a response to a group-specific or group-and-source-specific query message. (Range: 1-31744 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 is sent to the upstream multicast router.
A reduced value will result in reduced time to detect the loss of the last member of a group or source, but may generate more burst traffic.
This attribute will take effect only if IGMP snooping proxy reporting is enabled or IGMP querier is enabled.
The number of IGMP proxy group-specific or group-and-source-specific query messages that are sent out before the system assumes there are no more local members. (Range: 1-255; Default: 2)
This attribute will take effect only if IGMP snooping proxy reporting or IGMP querier is enabled.
A static source address for locally generated query and report messages used by IGMP Proxy Reporting. (Range: Any valid IP unicast address; Default: 0.0.0.0)
IGMP Snooping uses a null IP address of 0.0.0.0 for the source of IGMP query messages which are proxied to downstream hosts to indicate that it is not the elected querier, but is only proxying these messages as defined in RFC 4541. The switch also uses a null address in IGMP reports sent to upstream ports.
Many hosts do not implement RFC 4541, and therefore do not understand query messages with the source address of 0.0.0.0. These hosts will therefore not reply to the queries, causing the multicast router to stop sending traffic to them.
To resolve this problem, the source address in proxied IGMP query messages can be replaced with any valid unicast address (other than the router's own address).
Use the Multicast > IGMP Snooping > Interface (Configure Interface) page to configure an interface to drop IGMP query packets or multicast data packets.
Port or Trunk identifier.
Configures an interface to drop any IGMP query packets received on the specified interface. If this switch is acting as a Querier, this prevents it from being affected by messages received from another Querier.
Configures an interface to stop multicast services from being forwarded to users attached to the downstream port (i.e., the interfaces specified by this command).