H3C Technologies H3C S12500-X Series Switches - Manual (Page 153)

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Query interval for MLD: 125s
Other querier present time for MLD: 255s
Maximum query response time for MLD: 10s
Querier for MLD: FE80::200:5EFF:FE66:5100 (This router)
MLD groups reported in total: 1
Troubleshooting MLD
No member information exists on the receiver-side router
Symptom
When a host sends a message to announce its joining IPv6 multicast group G, no member information
of multicast group G exists on the immediate router.
Analysis
• The correctness of networking and interface connections and whether the protocol layer of the
interface is up directly affect the generation of IPv6 group member information.
• IPv6 multicast routing must be enabled on the router. MLD must be enabled on the interface
connecting to the host.
• If the MLD version on the router interface is lower than that on the host, the router cannot recognize
the MLD report from the host.
• If the mld group-policy command has been configured on an interface, the interface cannot receive
report messages that fail to pass filtering.
Solution
1. Use the display mld interface command to verify that the networking, interface connections, 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, that the interface is not correctly connected, or that the IPv6 address configuration is not
correctly done.
2. Use the display current-configuration command to verify that the IPv6 multicast routing is enabled.
If it is not enabled, use the ipv6 multicast routing command in system view to enable IPv6 multicast
routing. In addition, verify that MLD is enabled on the associated interfaces.
3. Use the display mld interface command to verify that the MLD 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 IPv6 multicast group G.
Inconsistent membership information on the routers on the same
subnet
Symptom
Different memberships are maintained on different MLD routers on the same subnet.