Configuring SA request messages

About SA request message configuration

By default, after receiving a new join message, a device waits for an SA message to obtain the multicast source information and to join the SPT. You can enable the device to request source information by sending SA request messages to an MSDP peer. This reduces the join latency.

An SA request policy enables the device to filter SA request messages from an MSDP peer by using an ACL that specifies the multicast groups.

Prerequisites

Before you enable the device to send SA requests, make sure you have disabled the SA message cache mechanism by the undo cache-sa-enable command.

Procedure

  1. Enter system view.

    system-view

  2. Enter MSDP view.

    msdp [ vpn-instance vpn-instance-name ]

  3. Enable the device to send SA request messages to an MSDP peer.

    peer peer-address request-sa-enable

    By default, after receiving a new join message, a device does not send an SA request message to any MSDP peer. Instead, it waits for the next SA message from its MSDP peer.

  4. Configure an SA request policy for an MSDP peer.

    peer peer-address sa-request-policy [ acl ipv4-acl-number ]

    By default, no SA request policy exists, and all SA request from an MSDP peer are permitted.