Configuring SA Caching

Context

To shorten the delay before obtaining multicast information, enable the SA caching function. The switch then caches (S, G) entities obtained from SA messages. When the switch receives a new Join message, it searches the local cache for the (*, G) entry carried in the message:

If the matching (S, G) entry is found, the switch adds the sender of the Join message to the shortest path tree (SPT) with source S as the root.
If no matching (S, G) entry is found, the switch must wait the SA message sent by the MSDP peer during the next period.

As (S, G) entries accumulate in the cache, a larger memory space is occupied. You can set the maximum number of (S, G) entries allowed in the cache to protect the switch against Denial of Service (DoS) attacks.

Procedure

Run system-view
The system view is displayed.
Run msdp [ vpn-instance vpn-instance-name ]
The MSDP view is displayed.
Run cache-sa-enable
The SA caching function is enabled.

By default, the SA caching function is enabled on the switch that has a remote MSDP peer specified.
(Optional) Run peer peer-address sa-cache-maximum sa-limit
The maximum number of (S, G) entries is set.

By default, a maximum of 8192 (S, G) entries can be saved in the SA cache.