HP 6125XLG R2306-HP 6125XLG Blade Switch IP Multicast Configuration Guide - Page 42

Figure 15 Changing an RPF route As shown in Figure 15, when no static multicast route is configured, Switch C's RPF neighbor on the path back to the source is Switch A, and the multicast data from the source travels through Switch A to Switch C. When a static multicast route is configured on Switch C with Switch B as its RPF neighbor on the path back to the source, the multicast data from the source travels along the path: Switch A to Switch B and then to Switch C. Creating an RPF route When a unicast route is blocked, multicast forwarding might be stopped due to lack of an RPF route. In this case, you can create an RPF route by configuring a static multicast route for a given multicast source, so that a multicast routing entry is created to guide multicast forwarding. Figure 16 Creating an RPF route Multicast Routing Table Static on Switch C Source/Mask Interface RPF neighbor/Mask 192.168.0.0/24 Vlan-int10 1.1.1.1/24 OSPF domain Switch D Receiver Multicast Routing Table Static on Switch D Source/Mask Interface RPF neighbor/Mask 192.168.0.0/24 Vlan-int20 2.2.2.2/24 Vlan-int20 2.2.2.1/24 Source 192.168.0.1/24 RIP domain Vlan-int10 Vlan-int10 1.1.1.1/24 1.1.1.2/24 Vlan-int20 2.2.2.2/24 Receiver Switch A Switch B Switch C Multicast packets Multicast static route As shown in Figure 16, the RIP domain and the OSPF domain are unicast isolated from each other. When no static multicast route is configured, the receiver hosts in the OSPF domain cannot receive the multicast packets from the multicast source in the RIP domain. If you configure a static multicast route on Switch C 35