H3C Technologies H3C SecPath F1000-E - Manual (Page 627)

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• If the IGMP version on the router interface is lower than that on the host, the router will not be able
to recognize the IGMP report from the host.
• If the igmp group-policy command has been configured on the interface, the interface cannot
receive report messages that fail 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 no information is output, the interface is in abnormal state.
The reason is that you have configured the shutdown command on the interface, that the interface
is not properly connected, or that the IP address configuration is not correctly done.
2. Use the display current-configuration command to verify that multicast routing is enabled. If not,
use the multicast routing-enable command in system view to enable IP multicast routing. In
addition, check that IGMP is enabled on the corresponding 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 restrict the host from joining the multicast group G. If the host is restricted from
joining the multicast group G, the ACL rule must be modified to allow receiving the reports for the
multicast group G.
Inconsistent memberships on routers on the same subnet
Symptom
Different memberships are maintained on different IGMP routers on the same subnet.
Analysis
• A router running IGMP maintains multiple parameters for each interface, and these parameters
influence one another, forming very complicated relationships. Inconsistent IGMP interface
parameter configurations for routers on the same subnet will surely result in inconsistency of
memberships.
• In addition, although an IGMP router is compatible with a host that runs a different IGMP version,
all routers on the same subnet must run the same version of IGMP. Inconsistent IGMP versions
running on routers on the same subnet also leads to inconsistency of IGMP memberships.
Solution
1. Use the display current-configuration command to verify the IGMP configuration on the interfaces.
2. Use the display igmp interface command on all routers on the same subnet to verify the
IGMP-related timer settings. Make sure the settings are consistent on all the routers.
3. Use the display igmp interface command to verify that all the routers on the same subnet are
running the same version of IGMP.