Variable definitions

The following table describes the Interface tab fields.

Field Description
IfIndex The interface on which IGMP is enabled.
QueryInterval The frequency (in seconds) at which IGMP host query packets are transmitted on the interface.
Ensure that the robustness value is the same as the configured value on the multicast router (IGMP querier).
The range is from 1–65535, and the default is 125.
Status Indicates whether or not the interface is active. The interface becomes active if any IGMP forwarding ports exist on the interface. If the VLAN has no port members or if all of the port members are disabled, the status is notInService.
Version The version of IGMP (1, 2, or 3) configured on this interface. For IGMP to function correctly, all routers on a LAN must use the same version. The default is version 2.
OperVersion The version of IGMP currently running on this interface.
Querier The address of the IGMP querier on the IP subnet to which this interface is attached.
QueryMaxResponseTime The maximum response time (in 1/10 seconds) advertised in IGMPv2 general queries on this interface. This field is a read-only field and is not configurable on the Ethernet Routing Switch 5000 Series .
WrongVersionQueries The number of queries received with an IGMP version that does not match the interface. IGMP requires that all routers on a LAN be configured to run the same version of IGMP. If queries are received with the wrong version, it indicates a version mismatch.
Joins The number of times a group membership is added on this interface; that is, the number of times an entry for this interface is added to the cache table. This number gives an indication of the amount of IGMP activity over time.
Robustness Specifies tuning for the expected packet loss of a network. This value is equal to the number of expected query packet losses for each serial query interval, plus 1. If you expect a network to lose query packets, you must increase the robustness value.
Ensure that the robustness value is the same as the configured value on the multicast router (IGMP querier).
The range is from 2 to 255, and the default is 2. The default value of 2 means that one query for each query interval can be dropped without the querier aging out.
LastMembQueryIntvl Sets the maximum response time (in tenths of a second) that is inserted into group-specific queries sent in response to leave group messages. This parameter is also the time between group-specific query messages. This value is not configurable for IGMPv1.
Decreasing the value reduces the time to detect the loss of the last member of a group. The range is from 0–255, and the default is 10 tenths of seconds. Nortel recommends configuring this parameter to values higher than 3. If a fast leave process is not required, Nortel recommends values above 10. (The value 3 is equal to 0.3 of a second, and 10 is equal to 1.0 second.)
RouterAlertEnable When enabled, this parameter instructs the router to ignore IGMP packets that do not contain the router alert IP option. When disabled (default setting), the router processes IGMP packets regardless of whether the router alert IP option is set or not. To maximize your network performance, Nortel recommends that you set this parameter according to the version of IGMP currently in use: IGMPv1—Disable, IGMPv2—Enable, IGMPv3—Enable.
FlushAction Flushes the specified table type:
  • none
  • flushGrpMem: group member table
  • flushMrouter: mrouter table