Chapter 8 WAN
EMG6765-Q10A User’s Guide
62
Multicast
Traditionally, IP packets are transmitted in one of either two ways - Unicast (1 sender - 1 recipient) or
Broadcast (1 sender - everybody on the network). Multicast delivers IP packets to a group of hosts on
the network - not everybody and not just 1.
Figure 25
Multicast Example
In the multicast example above, systems A and D comprise one multicast group. In multicasting, the
server only needs to send one data stream and this is delivered to systems A and D.
IGMP (Internet Group Multicast Protocol) is a network-layer protocol used to establish membership in a
multicast group - it is not used to carry user data. The EMG6765-Q10A supports both IGMP version 1
(
IGMP-v1
) and IGMP version 2 (
IGMP-v2
).
At start up, the EMG6765-Q10A queries all directly connected networks to gather group membership.
After that, the EMG6765-Q10A periodically updates this information. IP multicasting can be enabled/
disabled on the EMG6765-Q10A WAN interface in the Web Configurator (
WAN
). Select
None
to disable
IP multicasting on these interfaces.
8.4 Management WAN
Use this screen to view, change, or add your EMG6765-Q10A’s Internet access settings. Click
Configuration
>
Network
>
WAN
. The following screen opens.
Figure 26
Network > WAN > Management WAN
