Configuring C-BSRs

You must configure C-BSRs when you configure dynamic RP election.

To prevent a legal BSR from being replaced by a malicious host, configure a BSR policy to filter BSR messages by using an ACL that specifies the legal BSR addresses. It is used to prevent the legal BSR from being replaced by a malicious host.

Configure C-BSRs on devices that reside in the backbone network.

Because the BSR and other devices exchange a large amount of information in the PIM-SM domain, reserve a large bandwidth between C-BSRs and other devices.

The C-BSR configuration on the devices in the PIM-SM domain must be the same.

For a successful RPF check, configure static multicast routes to ensure that the next hop to a C-BSR is a tunnel interface when C-BSRs connect to other PIM devices through tunnels. For more information about static multicast routes, see "Configuring multicast routing and forwarding."

1. Enter system view.

   system-view

2. Enter PIM view.

   pim [ vpn-instance vpn-instance-name ]

3. Configure a C-BSR.

   c-bsr ip-address [ scope group-address { mask-length | mask } ] [ hash-length hash-length | priority priority ] *

4. (Optional.) Configure a BSR policy.

   bsr-policy ipv4-acl-number

   By default, no BSR policies are configured. All bootstrap messages are regarded as legal.