HP A5500 EI Switch Series, Руководство по настройке

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RPF route change
The topology structure of a multicast network is the same as that of a unicast network, and multicast
traffic follows the same transmission path that unicast traffic does. You can configure a multicast static
route for a given multicast source to change the RPF route to create a transmission path for multicast
traffic different from the transmission path for unicast traffic.
Figure 25 Changing an RPF route
As shown in Figure 25 , when no multicast static route is configured, Router C’s RPF neighbor on the path
back to Source is Router A, and the multicast information from Source travels along the path from Router
A to Router C, which is the unicast route between the two routers. When a multicast static route is
configured on Router C and Router B is configured as Router C’s RPF neighbor on the path back to
Source, the multicast information from Source travels from Router A to Router B and then to Router C.
RPF route creation
When a unicast route is blocked, multicast traffic forwarding might be stopped because of a lack of an
RPF route. You can configure a multicast static route for a given multicast source to create an RPF route
so that a multicast routing entry is created to guide multicast traffic forwarding regardless of whether a
unicast route is available.