Configuring SA message policies
To control the propagation of multicast source information, you can configure the following policies:
SA creation policy—Limits the multicast source information advertised in SA messages. This policy enables the router to advertise (S, G) entries by using an ACL that specifies the multicast sources and groups.
SA incoming or outgoing policy—Limits the receipt or forwarding of SA messages. This policy enables the router to receive or forward SA messages by using an ACL that specifies the multicast sources and groups.
By default, multicast data packets are encapsulated in SA messages and forwarded to MSDP peers only if the TTL values in the packets are larger than zero. You can set the lower TTL threshold for multicast data packets encapsulated in SA messages that are sent to an MSDP peer. Then, only multicast data packets whose TTL values are larger than or equal to the configured value are encapsulated in SA messages. Only SA messages whose TTL values are larger than or equal to the configured value are forwarded to the specified MSDP peer. This controls the multicast data packet encapsulation and limits the propagation range of the SA messages.
To configure SA message policies:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter MSDP view. | msdp [ vpn-instance vpn-instance-name ] | N/A |
3. Configure an SA creation policy. | import-source [ acl acl-number ] | By default, no SA creation policy exists. |
4. Configure an SA incoming or outgoing policy. | peer peer-address sa-policy { export | import } [ acl acl-number ] | By default, no SA incoming or outgoing policy exists. |
5. Set the lower TTL threshold for multicast data packets encapsulated in SA messages. | peer peer-address minimum-ttl ttl-value | The default setting is 0. |