Supported Platforms
Related Documentation
- ACX, J, M, MX, PTX, QFX, SRX, T Series
- Understanding IGMP
- EX, J, M, MX, PTX, QFX, SRX, T Series
- Modifying the IGMP Query Response Interval
- EX, M, MX, PTX, QFX, T Series
- Modifying the IGMP Robustness Variable
- EX, J, M, MX, PTX, QFX, T Series
- show igmp interface
- show igmp statistics
Modifying the IGMP Host-Query Message Interval
The objective of IGMP is to keep routers up to date with group membership of the entire subnet. Routers need not know who all the members are, only that members exist. Each host keeps track of which multicast groups are subscribed to. On each link, one router is elected the querier. The IGMP querier router periodically sends general host-query messages on each attached network to solicit membership information. The messages are sent to the all-systems multicast group address, 224.0.0.1.
The query interval, the response interval, and the robustness variable are related in that they are all variables that are used to calculate the group membership timeout. The group membership timeout is the number of seconds that must pass before a multicast router determines that no more members of a host group exist on a subnet. The group membership timeout is calculated as the (robustness variable x query-interval) + (query-response-interval). If no reports are received for a particular group before the group membership timeout has expired, the routing device stops forwarding remotely-originated multicast packets for that group onto the attached network.
By default, host-query messages are sent every 125 seconds. You can change this interval to change the number of IGMP messages sent on the subnet.
To modify the query interval:
- Configure the interval.[edit protocols igmp]user@host# set query-interval 200
The value can be from 1 through 1024 seconds.
- Verify the configuration by checking the IGMP Query Interval field in the output of the show igmp interface command.
- Verify the operation of the query interval by checking the Membership Query field in the output of the show igmp statistics command.
Related Documentation
- ACX, J, M, MX, PTX, QFX, SRX, T Series
- Understanding IGMP
- EX, J, M, MX, PTX, QFX, SRX, T Series
- Modifying the IGMP Query Response Interval
- EX, M, MX, PTX, QFX, T Series
- Modifying the IGMP Robustness Variable
- EX, J, M, MX, PTX, QFX, T Series
- show igmp interface
- show igmp statistics
Published: 2013-01-17
Supported Platforms
Related Documentation
- ACX, J, M, MX, PTX, QFX, SRX, T Series
- Understanding IGMP
- EX, J, M, MX, PTX, QFX, SRX, T Series
- Modifying the IGMP Query Response Interval
- EX, M, MX, PTX, QFX, T Series
- Modifying the IGMP Robustness Variable
- EX, J, M, MX, PTX, QFX, T Series
- show igmp interface
- show igmp statistics
