(Optional) Adjusting Control Parameters for Source Registration

Context

After receiving multicast data from a multicast source, the source DR encapsulates multicast data in a Register message and forwards the message to the RP. You can adjust control parameters for source registration on the RP and source DR.

You can perform the following operations on the source DR.

Configure the register message suppression time. After receiving a Register-Stop message, the source DR stops sending Register messages to the RP during register suppression. If the source DR receives no more Register-Stop messages, it forwards packets again when the register suppression time expires.
Configure the interval at which null Register messages are sent. If the timeout period for the register suppression state is too long or too short, multicast data cannot be forwarded normally. Sending null Register messages during the register suppression period can relieve this problem.
Configure the RP to calculate checksum based only on information in Register message headers. This reduces the checksum calculation time and improves the efficiency of multicast data encapsulation in Register messages.
Configure the source address for Register messages. The RP cannot receive Register messages from a source DR if the source address of the Register messages is not a unique IP address on the network or if the source address is filtered out by a policy configured on the RP. To enable the RP to receive Register messages from the source DR, configure a new source address for the Register messages.

You can perform the following operations on the RP.

Configure a policy to filter Register messages. You can specify the address range of Register messages to improve network security.

Default Settings

Table 1 lists the default settings of control parameters for source registration.

**Table 1** Default settings of control parameters for source registration
Parameter	Default Setting
Filter policy for Register messages	No filter policy configured (receiving Register messages with any group address)
Way to calculate the checksum	Based on the entire message
Register message suppression time	60s
Interval for sending null Register messages	5s

Procedure

Configure control parameters for source registration on the source DR.
1. Run system-view
  The system view is displayed.
2. Run pim [ vpn-instance vpn-instance-name | all-instance ]
  The PIM view is displayed.
3. Run register-suppression-timeout interval
  Register message suppression time is configured.
4. Run probe-interval interval
  The interval for sending null Register messages is configured.
  
  The value of probe-interval must be smaller than half of register-suppression-timeout.
5. Run register-header-checksum
  The checksum is calculated based only on the header of a Register message. Packets that fail the check are discarded.
6. Run register-source interface-type interface-number
  The source address of Register messages sent from the source DR is configured.
  
  It is recommended that you use the IP address of a loopback interface on the source DR as the source address of Register messages.
Configure control parameters for source registration on the RP.
1. Run system-view
  The system view is displayed.
2. Run pim [ vpn-instance vpn-instance-name | all-instance ]
  The PIM view is displayed.
3. Run register-policy advanced-acl-number
  A policy for filtering Register messages is configured.
  
  When configuring an ACL rule, use the permit parameter to configure the switch to accept only Register messages with addresses in a specified range. If no rule is configured in the ACL, the switch discards Register messages.