3Com Switch 8800 Advanced Software V5 Configuration Guide

Troubleshooting Multicast Routing and Forwarding 513
The configuration on Switch A, Switch B and Switch D is similar to the
configuration on Switch C. The specific configuration steps are omitted here.
3 Configure a multicast static route
# Configure a multicast static route on Switch C, specifying Switch D as its RPF
neighbor on the route to Source 2.
[SwitchC] ip rpf-route-static 10.220.5.0 255.255.255.0 192.168.3.2
4 Verify the configuration
# Before the above-mentioned multicast static route is configured, Receiver can
multicast data from Source 1, but cannot receive multicast data from Source 2.
Use the display multicast rpf-info command to view the RPF routes to Source 1
and Source 2 respectively on Switch C.
[SwitchC] display multicast rpf-info 10.110.5.100
RPF information about source 10.110.5.100:
RPF interface: Vlan-interface100, RPF neighbor: 10.110.1.1
Referenced route/mask: 10.110.5.0/24
Referenced route type: igp
Route selection rule: preference-preferred
Load splitting rule: disable
[SwitchC] display multicast rpf-info 10.220.5.100
As shown above, Switch C does not have an RPF route to Source 2.
# After the multicast static route is configured, use the display multicast
rpf-info command to view the RPF route to Source 2 again on Switch C.
[SwitchC] display multicast rpf-info 10.220.5.100
RPF information about source 10.220.5.100:
RPF interface: Vlan-interface300, RPF neighbor: 192.168.3.2
Referenced route/mask: 10.220.5.0/24
Referenced route type: multicast static
Route selection rule: preference-preferred
Load splitting rule: disable
As shown above, an RPF route to Source 2 has been established on Switch C.
Troubleshooting
Multicast Routing and
Forwarding
Multicast Static Route
Failure
Symptom
No dynamic routing protocol is enabled on the devices, and the physic status and
link layer status of interfaces are both up, but the multicast static route fails.
Analysis
■ If the multicast static route is not configured or updated correctly to match the
current network conditions, the route entry does not exist in the multicast
route configuration table and multicast routing table.
■ If the optimal route if found, the multicast static route may also fail.