(Optional) Configuring a Limit on the Number of PIM Entries

PIM-SSM allows you to limit the number of (S, G) entries. After a specified limit is reached, new (S, G) entries are not created.

Context

Limit the number of PIM (S, G) entries to prevent a device from generating excessive multicast routing entries when attackers send numerous multicast data or IGMP/PIM protocol messages. Therefore, this function helps prevent high memory and CPU usage and improve multicast service security.

Procedure

Run system-view
The system view is displayed.
Run multicast global limit pim sm source-group-number limit-count [ threshold-alarm upper-limit upper-limit-value lower-limit lower-limit-value ]
A limit on the number of (S, G) entries and alarm trigger and clear thresholds are set. After the command is run:
- After the specified limit is reached, new (S, G) entries are not created, and the PIM_1.3.6.1.4.1.2011.5.25.149.4.0.23 routeExceed alarm is generated.
  
  After the specified limit is reached, new (S, G) entries can be manually added.
- If threshold-alarm upper-limit upper-limit-value is set, the PIM_1.3.6.1.4.1.2011.5.25.149.4.0.21 routeThresholdExceed alarm is generated when the percentage ratio of created (S, G) entries to the specified limit reaches upper-limit-value.
Run commit
The configuration is committed.