Setting Parameters of the SA Request Message
Context
By default, a switch does not send SA Request message to its MSDP peer when receivers join a group. Instead, the switch waits a Source-Active (SA) message sent by the MSDP peer in the next period, which delays receiving of multicast source information on receivers. To enable new receivers to learn information about active multicast sources quickly, the switch needs to send an SA Request message to the MSDP peer in this case.
After receiving the SA Request message, the remote MSDP peer responds with a message containing the matching (S, G) information. If an SA Request message filtering rule is configured on the remote MSDP peer, the remote MSDP peer responds only to the SA Request messages permitted by the rule.
Before configuring a rendezvous point (RP) to send SA Request messages, disable the SA caching function on the RP and enable the SA caching function on its remote MSDP peer.
Procedure
- Run system-view
The system view is displayed.
- Run msdp [ vpn-instance vpn-instance-name ]
The MSDP view is displayed.
- Configure an RP to send SA Request messages.
Run peer peer-address request-sa-enable
The RP is configured to send SA Request messages.
- (Optional) Configure an SA Request message filtering rule
on the remote MSDP peer.
Run peer peer-address sa-request-policy [ acl basic-acl-number ]
An SA Request message filtering rule is configured.
When configuring an access control list (ACL), use the permit parameter to configure the switch to accept only SA Request messages with addresses in a specified range. If no rule is configured in the ACL, the switch discards all SA Request messages.