Multicast; Dns Servers; Lan - ZyXEL Communications 35 Series User Manual

Both RIP-2B and RIP-2M send routing data in RIP-2 format; the difference being that RIP-
2B uses subnet broadcasting while RIP-2M uses multicasting. Multicasting can reduce the
load on non-router machines since they generally do not listen to the RIP multicast address
and so will not receive the RIP packets. However, if one router uses multicasting, then all
routers on your network must use multicasting, also.
By default, RIP Direction is set to Both and RIP Version to RIP-1.

5.3.4 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 ZyWALL supports both IGMP version 1 (IGMP-v1) and IGMP version 2 (IGMP-v2). At
start up, the ZyWALL queries all directly connected networks to gather group membership.
After that, the ZyWALL periodically updates this information. IP multicasting can be enabled/
disabled on the ZyWALL LAN and/or WAN interfaces in the web configurator (LAN;
WAN). Select None to disable IP multicasting on these interfaces.

5.4 DNS Servers

Use the DNS LAN screen to configure the DNS server information that the ZyWALL sends to
the DHCP client devices on the LAN.

5.5 LAN

Click NETWORK, LAN to open the LAN screen. Use this screen to configure the
ZyWALL's IP address and other LAN TCP/IP settings as well as the built-in DHCP server
capability that assigns IP addresses and DNS servers to systems that support DHCP client
capability.
Chapter 5 LAN Screens
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