Multicast Forwarding Across Unicast Subnets - HP FlexNetwork 7500 Series Configuration Manual

Figure 24 Creating an RPF route
Multicast Routing Table Static on Router C
Source/Mask
192.168.0.0/24
Multicast Routing Table Static on Router D
Source/Mask
192.168.0.0/24
Source
192.168.0.1/24
Multicast packets
As shown in
The receiver hosts in the OSPF domain cannot receive the multicast packets from the multicast
source in the RIP domain. You can configure a static multicast route on Router C and Router D, and
specify Router B and Router C as the RPF neighbors of Router C and Router D, respectively. In this
way, the receiver hosts can receive the multicast data from the multicast source.
NOTE:
A static multicast route takes effect only on the multicast router on which it is configured, and will not
be advertised throughout the network or redistributed to other routers.

Multicast forwarding across unicast subnets

A network might have routers that do not support multicast protocols. When multicast data is
forwarded to a router of which the next hop supports only unicast protocols, the forwarding path is
blocked. To implement multicast forwarding across unicast subnets, you can establish a tunnel
between the multicast routers at the edges of the two unicast subnets.
Figure 25 Multicast data transmission through a tunnel
As shown in
Router A encapsulates multicast data in unicast IP packets, and forwards them to Router B across
Interface RPF neighbor/Mask
GE1/0/1 1.1.1.1/24
Interface RPF neighbor/Mask
GE1/0/1 2.2.2.2/24
RIP domain
Router A Router B
Figure 24, the RIP domain and the OSPF domain are unicast isolated from each other.
Figure 25, a tunnel is established between multicast routers Router A and Router B.
OSPF domain
Router D
GE1/0/2 GE1/0/1
1.1.1.1/24 1.1.1.2/24
Router C
Multicast static route
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Receiver
GE1/0/1
2.2.2.1/24
GE1/0/2
Receiver
2.2.2.2/24