H3C Technologies H3C S12500 Series Switches - Manual (Page 96)

80
Troubleshooting multicast routing and forwarding
Static multicast route failure
Symptom
No dynamic routing protocol is enabled on the routers, and the physical status and link layer status of
interfaces are both up, but the static multicast route fails.
Analysis
• If the static multicast route is not configured or updated correctly to match the current network
conditions, the route entry and the configuration information of static multicast route do not exist in
the multicast routing table.
• If a better route is found, the static multicast route might also fail.
Solution
1. Use the display multicast routing-table static command to view the information of static multicast
routes to verify that the static multicast route has been correctly configured and the route entry
exists in the multicast routing table.
2. Check the type of the next hop interface of the static multicast route. If the interface is not a
point-to-point interface, be sure to specify the next hop address for the outgoing interface when
you configure the static multicast route.
3. Check that the static multicast route matches the specified routing protocol. If a protocol was
specified in static multicast route configuration, enter the display ip routing-table command to
check if an identical route was added by the protocol.
4. Check that the static multicast route matches the specified routing policy. If a routing policy was
specified when the static multicast route was configured, enter the display route-policy command
to check the configured routing policy.
Multicast data fails to reach receivers
Symptom
The multicast data can reach some routers but cannot reach the last-hop router.
Analysis
If a multicast forwarding boundary has been configured through the multicast boundary command, any
multicast packet will be kept from crossing the boundary.
Solution
1. Use the display pim routing-table command to check whether the corresponding (S, G) entries
exist on the router. If so, the router has received the multicast data. Otherwise, the router has not
received the data.
2. Use the display multicast boundary command to view the multicast boundary information on the
interfaces. Use the multicast boundary command to change the multicast forwarding boundary
setting.
3. In the case of PIM-SM, use the display current-configuration command to check the BSR and RP
information.