Cerberus ADSL2+ Wi-Fi (P 6331-5)
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Application / IGMP Proxy
IP hosts use Internet Group Management Protocol (IGMP) to report their multicast group
memberships to neighboring routers. Similarly, multicast routers use IGMP to discover which
of their hosts belong to multicast groups. Your router supports IGMP proxy that handles IGMP
messages. When enabled, your router acts as a proxy for a LAN host making requests to join
and leave multicast groups, or a multicast router sending multicast packets to multicast groups
on the WAN side.
Multicasting is a form of limited broadcast. UDP is used to send datagram’s to all hosts that
belong to what is called a Host Group. A host group is a set of one or more hosts identified by
a single IP destination address. The following statements apply to host groups:
•
Anyone can join or leave a host group at will.
•
There are no restrictions on a host’s location.
•
There are no restrictions on the number of members that may belong to a host group.
•
A host may belong to multiple host groups.
•
Non-group members may send UDP datagram’s to the host group.
Multicasting is useful when the same data needs to be sent to more than one device. For
instance, if one device is responsible for acquiring data that many other devices need, then
multicasting is a natural fit. Note that using multicasting as opposed to sending the same data
to individual devices uses less network bandwidth. The multicast feature also enables you to
receive multicast video streams from multicast servers. The IGMP Proxy page allows you to
enable multicast on available WAN and LAN connections.
You can configure the WAN or LAN interface as one of the following:
Upstream
– The interface that IGMP requests from hosts are sent to the multicast router.
Downstream
– The interface data from the multicast router are sent to hosts in the multicast
group database.
Ignore
– No IGMP request nor data multicast are forwarded.
Summary of Contents for Cerberus ADSL2+ Lite
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