Configure IGMP snooping Basic Functions
In the configuration tasks of IGMP snooping, you should first enable the IGMP snooping function so that the configuration of the other functions can take effect.
Configuration Condition
Before configuring the basic functions of IGMP snooping, first complete the following task:
Enable IGMP snooping Function
After enabling IGMP snooping function, the device can run the IGMP snooping function.
Table 2-2 Enable IGMP snooping function
Step
|
Command
|
Description
|
Enter global configuration mode
|
configure terminal
|
-
|
Enable global IGMP snooping function
|
ip igmp snooping
|
Mandatory
By default, the global IGMP snooping function is not enabled.
|
Enable the IGMP snooping function of the specified VLAN
|
ip igmp snooping vlan vlan-id
|
Mandatory
By default, the IGMP snooping function is not enabled in the VLAN.
|
![note](/storage/images/Document/Maipu/note-icon.jpg)
-
After enabling the global IGMP snooping function, you can enable the IGMP snooping function of the specified VLAN.
Configure IGMP snooping Version
The configured IGMP snooping version and the processing rules of the IGMP protocol packets are as follows:
The configured IGMP snooping version is V3 and the device can process IGMP protocol packets of V1, V2 and V3;
The configured IGMP snooping version is V2 and the device can process the IGMP protocol packets of V1 and V2 and does not process V3 protocol packets, but make V3 protocol packets flood in VLAN.
The configured IGMP snooping version is V1 and the device can process the IGMP protocol packets of V1 and does not process V2 or V3 protocol packets, but make V2 and V3 protocol packets flood in VLAN.
Table 2-3 Configure IGMP snooping version
Step
|
Command
|
Description
|
Enter global configuration mode
|
configure terminal
|
-
|
Configure IGMP snooping version
|
ip igmp snooping vlan vlan-id version version-number
|
Optional
By default, the IGMP snooping version is 2.
|
Enable IGMP snooping L2 Forwarding
Usually, IGMP snooping forwards the multicast service packet in VLAN according to the multicast source IP address and multicast destination IP address. After configuring IGMP snooping L2 forwarding, IGMP snooping forwards multicast service packets in VLAN according to the multicast destination MAC address.
Table 2-4 IGMP snooping L2 forwarding
Step
|
Command
|
Description
|
Enter global configuration mode
|
configure terminal
|
-
|
Enable L2 multicast L2 forwarding function in the specified VLAN
|
ip igmp snooping vlan vlan-id l2-forwarding
|
Mandatory
By default, IP forwarding function of VLAN IGMP snooping L2 multicast of is enabled.
|
Enable L2 multicast IP forwarding function in the specified VLAN
|
ip igmp snooping vlan vlan-id ipmc l2-forwarding
|
Mandatory
By default, MAC forwarding function of IGMP snooping L2 multicast in VLAN is enabled.
|
![note](/storage/images/Document/Maipu/note-icon.jpg)
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Because 32 multicast IP addresses correspond to one multicast MAC address, and L2 forwarding can't specify multicast source forwarding, there may be multiple IP multicast source groups corresponding to the same MAC group. At this time, there will be forwarding conflict.