Enterasys Networks VH-2402S ユーザーズマニュアル

9033645-01

VH-2402S User Interface 41

IGMP Multicast Filtering

Multicasting is used to support real-time applications such as video

conferencing 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 which 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 on the hosts which
subscribed to this service.

This switch uses IGMP (Internet Group Management Protocol) to query

for any attached hosts who want to receive a specific multicast service.
The switch looks up the IP Multicast Group used for this service and adds

any port which received a similar request to that group. It then propagates

the service request on to any neighboring multicast switch/router to
ensure that it will continue to receive the multicast service. (For more