3com MSR 20-20 참조 매뉴얼

Public instance IGMP view, VPN instance IGMP view

None

Use the require-router-alert command to configure globally the router to 
discard IGMP messages that do not carry the Router-Alert option.

Use the undo require-router-alert command to restore the system default.

By default, the device does not check the Router-Alert option, namely it handles all 
the IGMP messages it received to the upper layer protocol for processing.

igmp require-router-alert, send-router-alert (IGMP view).

# Globally configure the router to discard IGMP messages that do not carry the 
Router-Alert option in the public instance.

<Sysname> system-view

[Sysname] igmp

[Sysname-igmp] require-router-alert 

reset igmp [ vpn-instance vpn-instance-name | all-instance ] group { all | interface 
interface-type interface-number { all | group-address [ mask { mask | mask-length } ] 
[ source-address [ mask { mask | mask-length } ] ] } }

User view

vpn-instance-name: VPN instance name, a case sensitive string of up to 31 
characters.

all-instance: Specifies all VPN instances.

all: Specifies to clear all IGMP forwarding entries.

interface interface-type interface-number: Clears the IGMP forwarding entries on 
the specified interface.

group-address: Multicast group address, in the range of 224.0.1.0 to 
239.255.255.255.

source-address: Multicast source address.

mask: Subnet mask of the multicast group/source address, 255.255.255.255 by 
default.

mask-length: Subnet mask length of the multicast group/source address. For a 
multicast group address, this argument has an effective value range of 4 to 32; for