Troubleshooting igmp, Symptom, Analysis – H3C Technologies H3C S7500E Series Switches User Manual
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[SwitchB] interface vlan-interface 100
[SwitchB-Vlan-interface100] igmp proxying enable
[SwitchB-Vlan-interface100] quit
[SwitchB] interface vlan-interface 200
[SwitchB-Vlan-interface200] igmp enable
[SwitchB-Vlan-interface200] quit
3) Verify
the
configuration
Use the display igmp interface command to view the IGMP configuration and operation
information on an interface. For example
# Display the IGMP configuration and operation information on VLAN-interface 100 of Switch B.
[SwitchB] display igmp interface vlan-interface 100 verbose
Vlan-interface100(192.168.1.2):
IGMP proxy is enabled
Current IGMP version is 2
Multicast routing on this interface: enabled
Require-router-alert: disabled
Version1-querier-present-timer-expiry: 00:00:20
Use the display igmp group command to view the IGMP multicast group information. For
example,
# Display the IGMP multicast group information on Switch A.
[SwitchA] display igmp group
Total 1 IGMP Group(s).
Interface group report information
Vlan-interface100(192.168.1.1):
Total 1 IGMP Groups reported
Group Address Last Reporter Uptime Expires
224.1.1.1 192.168.1.2 00:02:04 00:01:15
As shown above, IGMP reports from the hosts are forwarded to Switch A through the proxy
interface, VLAN-interface 100 on Switch B.
Troubleshooting IGMP
No Membership Information on the Receiver-Side Router
Symptom
When a host sends a report for joining multicast group G, there is no membership information of
the multicast group G on the router closest to that host.
Analysis
z
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.
z
Multicast routing must be enabled on the router, and IGMP must be enabled on the
interface connecting to the host.
z
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.
z
If the igmp group-policy command has been configured on the interface, the interface
cannot receive report messages that fail to pass filtering.