4000 Router Series IP Multicast Configuration Guide

Referenced route/mask: 50.1.1.0/24

Referenced route type: multicast static

Route selection rule: preference-preferred

Load splitting rule: disable

[RouterC] display multicast rpf-info 50.1.1.100

RPF information about source 50.1.1.100:

RPF interface: Ethernet1/2, RPF neighbor: 20.1.1.2

Referenced route/mask: 50.1.1.0/24

Referenced route type: multicast static

Route selection rule: preference-preferred

Load splitting rule: disable

The output shows that the RPF routes to the source 2 exist on Router B and Router C. These RPF routes are

the configured static multicast routes.

Multicast forwarding over GRE tunnels

Network requirements

As shown in Figure 20, multicast routing and PIM-DM are enabled on Router A and Router C. Router B

does not support multicast. OSPF is running on Router A, Router B, and Router C. Configure a GRE tunnel

so that the receiver host can receive the multicast data from the source.

Figure 20 Network diagram

Configuration procedure

1. Configure the IP address and mask for each interface as shown in Figure 20. (Details not shown.)

2. Enable OSPF on routers to make sure the network-layer among the routers is interoperable and the

routing information among the routers can be dynamically updated. (Details not shown.)

3. Configure a GRE tunnel:

# Create interface Tunnel 0 on Router A and specify the tunnel encapsulation mode as GRE over

IPv4.

<RouterA> system-view

[RouterA] interface tunnel 0 mode gre

# Configure the IP address for interface Tunnel 0 on Router A and specify its source and

destination addresses.

[RouterA-Tunnel0] ip address 50.1.1.1 24