Enterasys Networks 9034313-07 manual Configuring Igmp at Layer, About Multicasting

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.

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/

Configuring IGMP at Layer 2

Purpose

To configure IGMP snooping from the switch CLI.

Commands

For information about...	Refer to page...
show igmpsnooping	13-3
set igmpsnooping adminmode	13-3
set igmpsnooping interfacemode	13-4
set igmpsnooping groupmembershipinterval	13-4
set igmpsnooping maxresponse	13-5
set igmpsnooping mcrtrexpiretime	13-6
set igmpsnooping add-static	13-6
set igmpsnooping remove-static	13-7
show igmpsnooping static	13-8
show igmpsnooping mfdb	13-8
clear igmpsnooping	13-9

13-2 IGMP Configuration