Navigation
Table of Contents
Guide That Contains This Content
[+] Expand All
[-] Collapse All
Related Documentation
Limiting the Number of IGMP Multicast Group Joins on Logical Interfaces
The group-limit statement enables you to limit the number of IGMP multicast group joins for logical interfaces. When this statement is enabled on a router running IGMP version 2 (IGMPv2) or version 3 (IGMPv3), the limit is applied upon receipt of the group report. Once the group limit is reached, subsequent join requests are rejected.
When configuring limits for IGMP multicast groups, keep the following in mind:
- Each any-source group (*,G) counts as one group toward the limit.
- Each source-specific group (S,G) counts as one group toward the limit.
- Groups in IGMPv3 exclude mode are counted toward the limit.
- Multiple source-specific groups count individually toward the group limit, even if they are for the same group. For example, (S1, G1) and (S2, G1) would count as two groups toward the configured limit.
- Combinations of any-source groups and source-specific groups count individually toward the group limit, even if they are for the same group. For example, (*, G1) and (S, G1) would count as two groups toward the configured limit.
- Configuring and committing a group limit on a network that is lower than what already exists on the network results in the removal of all groups from the configuration. The groups must then request to rejoin the network (up to the newly configured group limit).
- You can dynamically limit multicast groups on IGMP logical interfaces using dynamic profiles.
To limit multicast group joins on an IGMP logical interface:
- Access the logical interface at the IGMP protocol hierarchy
level.[edit]user@host# edit protocols igmp interface interface-name
- Specify the group limit for the interface.[edit protocols igmp interface interface-name]user@host# set group-limit limit
