LevelOne GEL-1061, User Manual

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14
Multicast Filtering
This chapter describes how to configure the following multicast services:
◆
IGMP Snooping – Configures snooping and query parameters.
◆
Filtering and Throttling – Filters specified multicast service, or throttles the
maximum of multicast groups allowed on an interface.
◆
MLD Snooping – Configures snooping and query parameters for IPv6.
Overview
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 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 on to the hosts
which subscribed to this service.
Figure 258: Multicast Filtering Concept
This switch can use Internet Group Management Protocol (IGMP) to filter multicast
traffic. IGMP Snooping can be used to passively monitor or “snoop” on exchanges
between attached hosts and an IGMP-enabled device, most commonly a multicast
router. In this way, the switch can discover the ports that want to join a multicast
group, and set its filters accordingly.
Unicast
Flow
Multicast
Flow