3com 5500-ei pwr Instrução De Instalação

 

10 

To do... 

Use the command... 

Remarks  

Enter system view 

— 

Enter interface view 

interface interface-type interface-number 

— 

In VLAN 
interface view 

igmp group-policy 
acl-number [ 1 | 2 | port 
interface-list ] 

Configuring a multicast 
group filter  

In LoopBack 
interface view 

igmp group-policy 
acl-number [ 1 | 2 ] 

Optional 

No multicast group filter 
is configured by default  

 

Follow these steps to configure a multicast group filter in Ethernet port view: 

To do... 

Use the command... 

Remarks  

Enter system view 

— 

Enter Ethernet port view 

interface interface-type 
interface-number 

— 

Configuring a multicast group 
filter  

igmp group-policy 
acl-number vlan vlan-id 

Optional 

No multicast group filter is 
configured by default. The port 
must belong to the specified 
VLAN.  

 

Generally, hosts running IGMP respond to the IGMP query messages of the IGMP querier. If hosts fail to 

respond for some reason, the multicast router may consider that there is no member of the multicast 

group on the local subnet and remove the corresponding path.  

To avoid this situation from happening, you can enable simulated joining on a port of the switch, namely 

configure the port as a simulated member host for a multicast group. When the port receives IGMP 

query messages, the simulated member host will respond. As a result, the subnet attached to the Layer 

3 interface can continue to receive multicast traffic.  

Through this configuration, the following functions can be implemented: 

z 

When an Ethernet port is configured as a simulated member host, the switch sends an IGMP report 

through this port. Meanwhile, the simulated host sends the same IGMP report to itself and 

establishes a corresponding IGMP entry based on this report.  

z 

When receiving an IGMP general query, the simulated host responds with an IGMP report. 

Meanwhile, the simulated host sends the same IGMP report to itself to ensure that the IGMP entry 

does not age out.  

z 

When the simulated joining function is disabled on an Ethernet port, the simulated host sends an 

IGMP leave message. 

Therefore, to ensure that IGMP entries will not age out, the port must receive IGMP general queries 

periodically.