Related Documentation
- EX, J, M, MX, SRX, T Series
- Understanding MLD
- EX, J, M, MX, PTX, SRX, T Series
- Modifying the MLD Query Response Interval
- EX, J, M, MX, PTX, T Series
- show mld interface in the Junos OS Operational Mode Commands
- J, M, MX, PTX, SRX, T Series
- Example: Modifying the MLD Robustness Variable
Modifying the MLD Last-Member Query Interval
The last-member query interval (also called the last-listener query interval) is the maximum amount of time between group-specific query messages, including those sent in response to done messages sent on the link-scope-all-routers address FF02::2. You can lower this interval to reduce the amount of time it takes a router to detect the loss of the last member of a group.
When the routing device that is serving as the querier receives a leave-group (done) message from a host, the routing device sends multiple group-specific queries to the group. The querier sends a specific number of these queries, and it sends them at a specific interval. The number of queries sent is called the last-listener query count. The interval at which the queries are sent is called the last-listener query interval. Both settings are configurable, thus allowing you to adjust the leave latency. The IGMP leave latency is the time between a request to leave a multicast group and the receipt of the last byte of data for the multicast group.
The last-listener query count x (times) the last-listener query interval = (equals) the amount of time it takes a routing device to determine that the last member of a group has left the group and to stop forwarding group traffic.
The default last-listener query interval is 1 second. You can configure a subsecond interval up to one digit to the right of the decimal point. The configurable range is 0.1 through 0.9, then in 1-second intervals 1 through 999,999.
To modify this interval:
- Configure the time (in seconds) that the routing device
waits for a report in response to a group-specific query.[edit protocols mld]user@host# set query-last-member-interval 0.1
- Verify the configuration by checking the MLD Last Member Query Interval field in the output of the show igmp interfaces command.
 | Note: You can configure the last-member query count by configuring the robustness variable. The two are always equal. |
Related Documentation
- EX, J, M, MX, SRX, T Series
- Understanding MLD
- EX, J, M, MX, PTX, SRX, T Series
- Modifying the MLD Query Response Interval
- EX, J, M, MX, PTX, T Series
- show mld interface in the Junos OS Operational Mode Commands
- J, M, MX, PTX, SRX, T Series
- Example: Modifying the MLD Robustness Variable
Published: 2013-08-13
Related Documentation
- EX, J, M, MX, SRX, T Series
- Understanding MLD
- EX, J, M, MX, PTX, SRX, T Series
- Modifying the MLD Query Response Interval
- EX, J, M, MX, PTX, T Series
- show mld interface in the Junos OS Operational Mode Commands
- J, M, MX, PTX, SRX, T Series
- Example: Modifying the MLD Robustness Variable
