3Com 10014299 manual PIM-SM Configuration, Enabling Multicast Routing

516CHAPTER 36: CONFIGURING PIM-SM

neighbors. The hello message also takes charge of choosing a DR for the router operating IGMPv1.

■Register Message: When the DR receives the multicast message sent by the host in the local network, it encapsulates it in the register message and unicasts it to the RP to distribute the message along the RP tree. The source address in the IP header of the register message is DR address, and the destination address is RP address.

■Register-Stop Message: It is unicast to the transmitter of the register message by RP to inform the transmitter to stop sending register messages.

■Join/Prune Message: This message is sent in the direction of the source or RP. The join message establishes the RPT or SPT. When the receiver leaves the group, the prune message is used to prune the RPT or SPT. The join message and the prune message are placed in one message, but either of such two kinds of messages can be empty.

■Bootstrap Message: The router sends this message from all the interfaces except on that interface receiving this kind of message. This kind of message is generated in BSR, and is forwarded by all the routers. It is used to inform all the routers of the RP-Set information collected by BSR.

■Assert Message: When there are multiple routers in the multiple access network, and the output interface for the routing item of a router receives multicast message, this kind of message is used to specify the transmitter.

■Candidate-RP-Advertisement Message: This message is unicast to BSR by the candidate RP to report the service group address set of this candidate RP.

PIM-SM Configuration

Enabling Multicast

Routing

PIM-SM configuration includes tasks that are discribed in the following sections:

■Enabling Multicast Routing

■Starting the PIM-SM Protocol

■Configuring the Candidate BSR

■Configuring the Candidate RP

■Configuring the PIM-SM Domain Boundary

■Configuring the Time Interval for Sending a Hello Message

■Configuring the Threshold of the Shortest Path

Make the following configuration in the system view.

Table 587 Enable/Disable Multicast Routing

Operation	Command
Enable multicast routing	multicast routing-enable
Disable multicast routing	undo multicast routing-enable

By default, the system disables multicast routing.

Starting the PIM-SMThe PIM-SM protocol is configured at each interface in turn. In normal conditions, Protocol the PIM-SM protocol should be started at all interfaces.

Make the following configuration in the interface view.