HP 4800G Series Configuration Manual page 781

Switch A, Switch B and Switch C run OSPF.
Typically, Receiver can receive the multicast data from Source through the path Switch A – Switch
B, which is the same as the unicast route.
Perform the following configuration so that Receiver can receive the multicast data from Source
through the path Switch A – Switch C – Switch B, which is different from the unicast route.
Network diagram
Figure 1-4 Network diagram for RPF route alternation configuration
Configuration procedure
1) Configure IP addresses and unicast routing
Configure the IP address and subnet mask for each interface as per
configuration steps are omitted here.
Enable OSPF on the switches in the PIM-DM domain. Ensure the network-layer interoperation among
the switches in the PIM-DM domain. Ensure that the switches can dynamically update their routing
information by leveraging the unicast routing protocol. The specific configuration steps are omitted
here.
2) Enable IP multicast routing, and enable PIM-DM and IGMP
# Enable IP multicast routing on Switch B, enable PIM-DM on each interface, and enable IGMP on the
host-side interface VLAN-interface 100.
<SwitchB> system-view
[SwitchB] multicast routing-enable
[SwitchB] interface vlan-interface 100
[SwitchB-Vlan-interface100] igmp enable
[SwitchB-Vlan-interface100] pim dm
[SwitchB-Vlan-interface100] quit
[SwitchB] interface vlan-interface 101
[SwitchB-Vlan-interface101] pim dm
[SwitchB-Vlan-interface101] quit
1-11
Figure 1-4. The detailed