show ip igmp settings

Query Interval

How often the router will query an interface for group membership.

Configured Query Interval

The query interval that has been configured for the router.

Max Response Time

The length of time in seconds that the router will wait for an IGMP (V1 or V2) response from an interface before concluding that the group member on that interface is down and removing it from the group.

Group Membership Time

The length of time in seconds that a group will remain active on an interface in the absence of a group report.

Operating Version

The IGMP version operating on the router.

Configured Version

The IGMP version configured on the router.

Robustness Variable

Allows tuning for the expected packet loss on a network. If a network is expected to be lossy, the Robustness Variable may be increased. IGMP is robust to (Robustness Variable -1) packet losses. The Robustness Variable must not be zero, and should not be one. Default: 2

Router Alert Check

IGMP (v2/v3) messages have a router-alert option in the IP header. By default, this is validated by the router and it drops the packets without the router-alert option. If this check is disabled, IGMP messages without the router-alert option are accepted.

Last Member Query Interval

The Max Response Time used to calculate the Max Resp Code inserted into Group-Specific Queries sent in response to Leave Group messages. It is also the Max Response Time used in calculating the Max Resp Code for Group-and-Source-Specific Query messages. Default: 10 (1 second)

Last Member Query Count

The number of Group-Specific Queries sent before the router assumes there are no local members. The Last Member Query Count is also the number of Group-and-Source-Specific Queries sent before the router assumes there are no listeners for a particular source. Default: Robustness Variable.

Older Host Present Timer

The Older Host Present Interval is the time-out for transitioning a group back to IGMPv3 mode when an older version report is sent for that group. When an older version report is received, routers set their Older Host Present Timer to the Older Host Present Interval.

This value must be the (Robustness Variable x the Query Interval) + one Query Response Interval.

Maximum Group Address

Indicates the maximum number of group addresses that can be accepted by the router.