About Multicasting; Configuring Igmp At Layer 2 - Enterasys SECURESTACK C3 Configuration Manual

Configuring IGMP at Layer 2

About Multicasting

Multicasting is used to support real‐time applications such as video conferences or streaming
audio. A multicast server does not have to establish a separate connection with each client. It
merely broadcasts its service to the network, and any hosts that want to receive the multicast
register with their local multicast switch/router. Although this approach reduces the network
overhead required by a multicast server, the broadcast traffic must be carefully pruned at every
multicast switch/router it passes through to ensure that traffic is only passed to the hosts that
subscribed to this service.
The SecureStack C3 switch device uses IGMP (Internet Group Management Protocol) to query for
any attached hosts who want to receive a specific multicast service. The device looks up the IP
Multicast Group used for this service and adds it to the egress list of the Level 3 interface. It then
propagates the service request on to any neighboring multicast switch/router to ensure that it will
continue to receive the multicast service.
Configuring IGMP at Layer 2
Purpose
To configure IGMP snooping from the switch CLI.
Commands
For information about...
show igmpsnooping
set igmpsnooping adminmode
set igmpsnooping interfacemode
set igmpsnooping groupmembershipinterval
set igmpsnooping maxresponse
set igmpsnooping mcrtrexpiretime
set igmpsnooping add-static
set igmpsnooping remove-static
show igmpsnooping static
show igmpsnooping mfdb
clear igmpsnooping
13-2 IGMP Configuration
Note: An Enterasys Networks Feature Guide document containing an in-depth discussion of
multicast configuration is located on the Enterasys Networks web site:
http://www.enterasys.com/support/manuals/
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