H3C Technologies H3C SecPath F1000-E - Manual (Page 60)

26
Solution
Step1 Check that the networking, interface connection, and IP address configuration are correct. Check the
interface information with the display igmp interface command. If there is no information output,
the interface is in an abnormal state. This is usually because you have configured the shutdown
command on the interface, the interface is not properly connected, or the IP address configuration is not
correctly done.
Step2 Check that multicast routing is enabled. Carry out the display current-configuration command to
check whether the multicast routing-enable command has been executed. If not, carry out the
multicast routing-enable command in system view to enable IP multicast routing. In addition, check
that IGMP is enabled on the corresponding interfaces.
Step3 Check the IGMP version on the interface. You can use the display igmp interface command to
check whether the IGMP version on the interface is lower than that on the host.
Step4 Check that no ACL rule has been configured to restrict the host from joining the multicast group G. Carry
out the display current-configuration interface command to check whether the igmp
group-policy command has been executed. 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 is running 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
Step1 Check the IGMP configuration. Carry out the display current-configuration command to view the
IGMP configuration information on the interfaces.
Step2 Carry out the display igmp interface command on all routers on the same subnet to check the
IGMP-related timer settings. Make sure that the settings are consistent on all the routers.
Step3 Use the display igmp interface command to check whether all the routers on the same subnet are
running the same version of IGMP.