Configuring a BSR RP

Select several routers and configure them as Candidate-BootStrap Routers (C-BSRs) and Candidate-Rendezvous Points (C-RPs). A BSR is dynamically elected from C-BSRs. The BSR collects C-RP information and summarizes C-RP information into an RP-Set. The RP-Set is encapsulated in a Bootstrap message and advertised to all the routers in the PIM domain. Then, the C-RPs elect a BSR RP based on a uniform election rule.

Context

If a network is divided into several PIM-SM domains and the BSR RP needs to be used, configure a BSR boundary on the interfaces of edge routers in PIM-SM domains to limit the range of each PIM-SM domain. Then, configure C-BSRs and C-RPs in each PIM-SM domain.

Procedure

Run system-view
The system view is displayed.
Configure a basic numbered ACL or a named ACL as needed.
- Configure a basic numbered ACL.
  1. Run acl [ number ] basic-acl-number [ match-order { auto | config } ]
    A basic numbered ACL is created, and the basic numbered ACL view is displayed.
  2. Run rule [ rule-id ] [ name rule-name ] { deny | permit } source { source-ip-address { source-wildcard | 0 } | any }
    Rules are configured for the basic numbered ACL.
- Configure a named ACL.
  1. Run acl name acl-name basic [ match-order { auto | config } ]
    A named ACL is created, and the named ACL view is displayed.
  2. Run rule [ rule-id ] [ name rule-name ] { deny | permit } source { source-ip-address { source-wildcard | 0 } | any }
    Rules are configured for the named ACL.
If a basic numbered ACL is used, run the rule command and set the source parameter to the multicast group range to be served by the C-RP.

If a named ACL is used, run the rule command and set the destination parameter to the multicast group range to be served by the C-RP.
Run quit
Return to the system view.
Run pim [ vpn-instance vpn-instance-name ]
The PIM view is displayed.
Run c-bsr interface-type interface-number [ hash-length [ priority ] ]
The C-BSR is configured.
- interface-type interface-number: specifies the interface where the C-BSR resides. The interface must be configured with PIM-SM.
  
  To avoid frequent protocol changes caused by interface flapping, using loopback interfaces is recommended.
- hash-length: specifies the length of the hash mask.
  
  Based on the group address G, C-RP addresses, and value of hash-length, the router calculates the hash value of the C-RPs that have the same priority and want to serve group G. The C-RP with the largest hash value is elected as the RP for group G.
  
  When a multicast network is overloaded or traffic congests on an RP, the RP may be overburdened. In this situation, you can configure hash-length to enable different RPs to transmit services for different multicast groups and implement load balancing.
- priority: specifies the C-BSR priority for BSR election. A larger priority value indicates a higher priority.
  
  In a BSR election, the C-BSR with the highest priority wins. If all C-BSRs have the same priority, the C-BSR with the largest IP address wins.
Run c-rp interface-type interface-number [ group-policy { basic-acl-number | acl-name acl-name } | priority priority | holdtime hold-interval | advertisement-interval adv-interval ] ^*
- A C-RP is configured. interface-type interface-number: specifies the interface where the C-RP resides. The interface must be configured with PIM-SM.
  
  To avoid frequent protocol changes caused by interface flapping, using loopback interfaces is recommended.
  
  If IP address unnumbered is enabled, do not configure the interfaces with the same address as C-RPs simultaneously. If the priorities of C-RPs are different, the BSR considers that the C-RP configuration is frequently modified.
- group-policy basic-acl-number: specifies that the C-RP serves only the multicast groups matching the ACL.
- priority priority: specifies the C-RP priority for RP election. A larger priority value indicates a higher priority.
  
  The RP election rules are as follows:
  - If interfaces have the same address mask, the C-RP with the highest priority wins.
  - If interfaces have the same priority, the hash function is used and the C-RP with the largest hash value wins.
  - If interfaces have the same priority and the same hash value, the C-RP with the largest IP address wins.
- holdtime hold-interval: specifies the timeout period for the BSR to wait for an Advertisement message from the C-RP.
- advertisement-interval adv-interval: specifies the interval for the C-RP to send Advertisement messages.
- If no ACL is configured, the C-RP serves all multicast groups.
- If an ACL is configured, the device uses configured ACL rules to filter multicast groups to be served by the C-RP.
  - If a multicast group matches an ACL rule and the action is permit, the C-RP serves this multicast group.
  - If a multicast group matches an ACL rule and the action is deny, the C-RP does not serve this multicast group.
  - If a multicast group does not match any ACL rule or if a specified ACL does not exist or does not contain rules, the C-RP serves all multicast groups.
(Optional) Run bsm semantic fragmentation
BSR packet fragmentation is enabled.

Enabling BSR packet fragmentation on all devices is recommended because BSR packet fragmentation can solve the problem faced by IP fragmentation that all fragments become unavailable due to loss of fragment information.
(Optional) Run auto-rp listening enable
Auto-RP listening is enabled.

Configure this command if the router needs to interwork with a device that supports Auto-RPs.
Run commit
The configuration is committed.