Atlantis Land 111U User Manual
Page 41
41
4.
None - the ADSL Router will not send any RIP packets and will ignore any
RIP packets received.
The Dynamic Route field controls the format and the broadcasting method of the RIP
packets that the ADSL Router sends (it recognizes both formats when receiving). RIP-
1 is universally supported; but RIP-2 carries more information. RIP-1 is probably
adequate for most networks, unless you have an unusual network topology.
Both RIP-2B and RIP-2M sends the routing data in RIP-2 format; the difference being
that RIP-2B uses subnet broadcasting while RIP-2M uses multicasting.
6.4.4 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.
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. IGMP version 2
(RFC 2236) is an improvement over version 1 (RFC 1112) but IGMP version 1 is still in
wide use. If you would like to read more detailed information about interoperability
between IGMP version 2 and version 1, please see sections 4 and 5 of RFC 2236. The
class D IP address is used to identify host groups and can be in the range 224.0.0.0 to
239.255.255.255. The address 224.0.0.0 is not assigned to any group and is used by
IP multicast computers. The address 224.0.0.1 is used for query messages and is
assigned to the permanent group of all IP hosts (including gateways). All hosts must
join the 224.0.0.1 group in order to participate in IGMP. The address 224.0.0.2 is
assigned to the multicast routers group.
The ADSL Router supports both IGMP version 1 (IGMP-v1) and IGMP version 2 (IGMP-
v2). At start up, the ADSL Router queries all directly connected networks to gather
group membership. After that, the ADSL Router periodically updates this information.
IP multicasting can be enabled/disabled on the ADSL Router LAN and/or WAN
interfaces in the web configurator (LAN; WAN). Select None to disable IP multicasting
on these interfaces.