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 device to advertise (S, G) entries based on the used 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 device to receive or forward SA messages based on the used ACL that specifies the multicast sources and groups.

• The lower TTL threshold for multicast data packets encapsulated in SA messages—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.

1. Enter system view.

   system-view

2. Enter MSDP view.

   msdp [ vpn-instance vpn-instance-name ]

3. Configure an SA creation policy.

   import-source [ acl ipv4-acl-number ]

4. Configure an SA incoming or outgoing policy.

   peer peer-address sa-policy { export | import } [ acl ipv4-acl-number ]

   By default, no SA incoming or outgoing policy is configured. The device does not filter incoming or outgoing SA messages.

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.