l2-multicast fast-channel group-address (VLAN view)

Function

The l2-multicast fast-channel group-address command enables prompt join.

The undo l2-multicast fast-channel group-address command disables prompt join.

By default, prompt join is disabled.

Format

l2-multicast fast-channel [ source-address source-address { SrcAddrMask | SrcAddrMaskLen } ] group-address group-address { GrpAddrMask | GrpAddrMaskLen }

undo l2-multicast fast-channel [ source-address source-address { SrcAddrMask | SrcAddrMaskLen } ] group-address group-address { GrpAddrMask | GrpAddrMaskLen }

Parameters

Parameter	Description	Value
source-address source-address	Specifies a source address.	The IP address can be a class A, B, or C address, in dotted decimal notation.
SrcAddrMask	Specifies the mask of a source address.	The value is in dotted decimal notation.
SrcAddrMaskLen	Specifies the mask length of a source address.	The value is an integer ranging from 16 to 32.
group-address	Specifies the IP address of a multicast group.	The value ranges from 224.0.1.0 to 239.255.255.255, in dotted decimal notation.
GrpAddrMask	Specifies the mask of a multicast group address.	The value is in dotted decimal notation.
GrpAddrMaskLen	Specifies the mask length of a multicast group address.	The value is an integer ranging from 16 to 32.

Views

VLAN view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
l2mc	write

Usage Guidelines

Usage Scenario

After receiving the first IGMP Report for a multicast group, a device needs to apply for resources for this group and then generates a forwarding entry. This decreases the speed at which hosts join the multicast group. After the prompt join function is enabled on a device, the device applies for resources for multicast groups in advance. When the device receives an IGMP Report message for a multicast group, it can immediately forward multicast data for the multicast group, increasing the speed at which hosts join the multicast group and shortening the delay for the device to respond to the Report message.

Configuration Impact

If a device has reserved resources for a multicast group but does not receive an IGMP Report message for this multicast group for a long period of time, resources will be wasted and device performance will be degraded.

Example

# Enable prompt leave in VLAN 10.

<HUAWEI> system-view
[~HUAWEI] igmp-snooping enable
[~HUAWEI] vlan 10
[*HUAWEI-vlan10] l2-multicast fast-channel source-address 10.2.2.2 32 group-address 232.0.0.1 32