4.9 IGMP Snooping

The Internet Group Management Protocol (IGMP) lets host and routers share information about multicast groups memberships. IGMP snooping is a switch feature that monitors the exchange of IGMP messages and copies them to the CPU for feature processing. The overall purpose of IGMP Snooping is to limit the forwarding of multicast frames to only ports that are a member of the multicast group.

4.9.1 IGMP Snooping Configuration

The IGMP Configuration page let the administrator to configure the parameters for IGMP Snooping, which is used to build forwarding lists for multicast traffic. The screen in Figure 4-35 appears.

Figure 4-35IGMP Snooping Configuration and Status

The page includes the following fields: table 4-17 description of the IGMP Snooping Configuration.

 

• Item

Description

 

 

 

 

 

 

• IGMP Enable

Enables or disables IGMP global function on the device.

 

 

 

Disabled is the default value.

 

 

 

 

 

 

• Router Ports

The Router Ports check box fields for attaching ports to a device that is attached

 

 

 

to a neighboring Multicast router/switch. Once IGMP Snooping is enabled,

 

 

 

Multicast packets are forwarded to the appropriate port .

 

 

 

 

 

 

• Unregistered IPMC

The function is to set “Enable” or “Disable” to allow the unregistered IP Multicast

 

 

Flooding Enable

Group streams to flood to all ports of this switch. The unregistered IP Multicast

 

 

 

means that the received Multicast Group address not listed in the Multicast Group

 

 

 

Table of the switch.

 

 

 

Enabled is the default value. The switch forwards all the multicast steams to all

 

 

 

the host or linked switch.

 

 

 

 

 

 

• VLAN ID

Identifies a VLAN and contains information about the Multicast group

 

 

 

 

 

 

 

 

 

 

 

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