R21xx-HP FlexFabric 11900 IP Multicast Configuration Guide

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Troubleshooting IGMP
No membership information on the receiver-side router
Symptom
When a host sends a report for joining the multicast group G, no membership information of the multicast
group G exists on the router closest to that host.
Analysis
• The correctness of networking and interface connections and whether the protocol layer of the
interface is up directly affect the generation of group membership information.
• Multicast routing must be enabled on the router. IGMP must be enabled on the interface that
connects to the host.
• If the IGMP version on the router interface is lower than that on the host, the router cannot recognize
the IGMP report from the host.
• If you have configured the igmp group-policy command on the interface, the interface cannot
receive report messages that failed to pass filtering.
Solution
1. Use the display igmp interface command to verify that the networking, interface connection, and
IP address configuration are correct. If the command does not produce output, the interface is in an
abnormal state. The reason might be that you have configured the shutdown command on the
interface, the interface is not correctly connected, or the IP address configuration is not correctly
completed.
2. Use the display current-configuration command to verify that multicast routing is enabled. If it is not
enabled, use the multicast routing-enable command in system view to enable IP multicast routing.
In addition, verify that IGMP is enabled on the associated interfaces.
3. Use the display igmp interface command to verify that the IGMP version on the interface is lower
than that on the host.
4. Use the display current-configuration interface command to verify that no ACL rule has been
configured to filter out the reports sent by the host to the multicast group G.
Inconsistent membership information on the routers on the same
subnet
Symptom
Different memberships are maintained on different IGMP routers on the same subnet.