3Com 10014299 PIM-SM Configuration

516 CHAPTER 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 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
Enabling Multicast
Routing Make the following configuration in the system view.
Tabl e 587 Enable/Disable Multicast Routing
By default, the system disables multicast routing.
Starting the PIM-SM
Protocol The PIM-SM protocol is configured at each interface in turn. In normal conditions, the PIM-SM protocol should be started at all interfaces.
Make the following configuration in the interface view.
Operation Command
Enable multicast routing multicast routing-enable
Disable multicast routing undo multicast routing-enable