H3C Technologies H3C S12500 Series Switches - Manual (Page 35)

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• Configure the corresponding VLANs.
• Determine the version of IGMP snooping.
Enabling IGMP snooping
When you enable IGMP snooping, follow these guidelines:
• You must enable IGMP snooping globally before you enable it in a VLAN.
• If you enable IGMP snooping for a VLAN, do not enable IGMP or PIM on the corresponding VLAN
interface. If you enable IGMP or PIM on a VLAN interface, do not enable IGMP snooping for the
VLAN.
• IGMP snooping for a VLAN works on only the ports in this VLAN.
To enable IGMP snooping:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enable IGMP snooping globally
and enter IGMP-snooping view.
igmp-snooping Disabled by default.
3. Return to system view. quit N/A
4. Enter VLAN view. vlan vlan-id N/A
5. Enable IGMP snooping in the
VLAN.
igmp-snooping enable Disabled by default.
Specifying the IGMP snooping version
Different versions of IGMP snooping can process different versions of IGMP messages:
• IGMPv2 snooping can process IGMPv1 and IGMPv2 messages, but flood IGMPv3 messages in the
VLAN instead of processing them.
• IGMPv3 snooping can process IGMPv1, IGMPv2 and IGMPv3 messages.
If you change IGMPv3 snooping to IGMPv2 snooping, the system does the following:
• Clears all IGMP snooping forwarding entries that are dynamically added.
• Keeps static IGMPv3 snooping forwarding entries (*, G).
• Clears static IGMPv3 snooping forwarding entries (S, G), which will be restored when IGMP
snooping is switched back to IGMPv3 snooping.
For more information about static joins, see " Configuring static ports ."
To specify the version of IGMP snooping:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter VLAN view. vlan vlan-id N/A
3. Specify the version of IGMP
snooping. igmp-snooping version
version-number
IGMPv2 snooping by default.