Troubleshooting Mld Snooping; Switch Fails In Layer 2 Multicast Forwarding - 3Com 4210G Series Configuration Manual

[SwitchB] ipv6
[SwitchB] mld-snooping
[SwitchB-mld-snooping] quit
# Create VLAN 100, add GigabitEthernet 1/0/1 through GigabitEthernet 1/0/4 into VLAN 100.
[SwitchB] vlan 100
[SwitchB-vlan100] port gigabitethernet 1/0/1 to gigabitethernet 1/0/4
# Enable the MLD Snooping feature in VLAN 100.
[SwitchB-vlan100] mld-snooping enable
[SwitchB-vlan100] quit
Configurations of Switch C and Switch D are similar to the configuration of Switch B.
3) Verify the configuration
When the MLD Snooping querier starts to work, all the switches but the querier receive MLD general
queries. Use the display mld-snooping statistics command to view the statistics information of these
MLD messages received.
# View the MLD message statistics on Switch B.
[SwitchB-vlan100] display mld-snooping statistics
Received MLD general queries:3.
Received MLDv1 specific queries:0.
Received MLDv1 reports:12.
Received MLD dones:0.
Sent MLDv1 specific queries:0.
Received MLDv2 reports:0.
Received MLDv2 reports with right and wrong records:0.
Received MLDv2 specific queries:0.
Received MLDv2 specific sg queries:0.
Sent MLDv2 specific queries:0.
Sent MLDv2 specific sg queries:0.
Received error MLD messages:0.

Troubleshooting MLD Snooping

Switch Fails in Layer 2 Multicast Forwarding

Symptom
A switch fails to implement Layer 2 multicast forwarding.
Analysis
MLD Snooping is not enabled.
Solution
1) Enter the display current-configuration command to view the running status of MLD Snooping.
2) If MLD Snooping is not enabled, use the mld-snooping command to enable MLD Snooping
globally, and then use mld-snooping enable command to enable MLD Snooping in VLAN view.
3) If MLD Snooping is disabled only for the corresponding VLAN, just use the mld-snooping enable
command in VLAN view to enable MLD Snooping in the corresponding VLAN.
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