3com S7906E インストール手順

 

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By default, for the consideration of compatibility, the device does not check the Router-Alert option, 

namely it processes all the IGMP messages it received. In this case, IGMP messages are directly 

passed to the upper layer protocol, no matter whether the IGMP messages carry the Router-Alert 

option or not.  

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To enhance the device performance and avoid unnecessary costs, and also for the consideration 

of protocol security, you can configure the device to discard IGMP messages that do not carry the 

Router-Alert option.  

Follow these steps to configure IGMP packet options globally:  

To do... 

Use the command... 

Remarks  

Enter system view 

— 

Enter public instance IGMP 
view or VPN instance IGMP 
view 

igmp [ vpn-instance 
vpn-instance-name ] 

— 

Configure the router to discard 
any IGMP message that does 
not carry the Router-Alert 
option  

require-router-alert 

Optional 

By default, the device does not 
check the Router-Alert option. 

Enable insertion of the 
Router-Alert option into IGMP 
messages  

Optional 

By default, IGMP messages 
carry the Router-Alert option.  

 

Follow these steps to configure IGMP packet options on an interface:  

To do... 

Use the command... 

Remarks  

Enter system view 

— 

Enter interface view 

interface interface-type 
interface-number 

— 

Configure the interface to 
discard any IGMP message 
that does not carry the 
Router-Alert option  

igmp require-router-alert 

Optional 

By default, the device does not 
check the Router-Alert option. 

Enable insertion of the 
Router-Alert option into IGMP 
messages  

igmp send-router-alert 

Optional 

By default, IGMP messages 
carry the Router-Alert option.  

 

On startup, the IGMP querier sends “startup query count” IGMP general queries at the “startup query 

interval”, which is 1/4 of the “IGMP query interval”.  

The IGMP querier periodically sends IGMP general queries at the “IGMP query interval” to determine 

whether any multicast group member exists on the network. You can tune the IGMP general query 

interval based on actual condition of the network.