3com S7906E Instruccion De Instalación
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[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.
Solution
1) 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.
2) 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