ZyXEL Communications Prestige 1600 - Manual (Page 47)

Prestige 1600 Universal Access Concentrator
Internet Access 5-3
5.1.2 Standalone IP Pool
When the Prestige Configuration Type (Menu 1) is set up as Standalone and Internet access is configured
through the Ethernet port, you have to manually enter Ethernet TCP/IP information using Menu 3. There are no
dynamic default IP address assignments in this scenario. The default route has to be configured in Menu 12.
5.2 TCP/IP Parameters
If you wish to know more about TCP/IP, please read on. Or you can skip to 4.3 TCP/IP Ethernet Setup for the
actual configuration.
5.2.1 IP Address and Subnet Mask
Machines on a LAN share one common network number; once you have decided on the network number, pick an
IP address that is easy to remember, e.g., 192.168.1.1, for your Prestige 1600.
The subnet mask specifies the network number portion of an IP address. Your Prestige 1600 will compute the
subnet mask automatically based on the IP address that you entered. You don’t need to change the subnet mask
computed by the Prestige 1600 unless you are instructed to do otherwise.
5.2.2 RIP Setup
RIP (Routing Information Protocol) allows a router to exchange routing information with other routers. The RIP
Direction field controls the sending and receiving of RIP packets. When set to:
1. Both - the Prestige 1600 will broadcast its routing table periodically and incorporate the RIP information that it
receives.
2. In Only - the Prestige will not send any RIP packets but will accept all RIP packets received.
3. Out Only - the Prestige will send out RIP packets but will not accept any RIP packets received.
4. None - the Prestige will not send any RIP packets and will ignore any RIP packets received.
The Version field controls the format and the broadcasting method of the RIP packets that the Prestige 1600 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 a 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.
5.2.3 IP Multicast
Traditionally, IP packets are transmitted in one of either two ways - Unicast (1 sender to 1 recipient) or Broadcast
(1 sender to everybody on the network). IP Multicast is a third way to deliver IP packets to a group of hosts on the
network - not everybody.
IGMP (Internet Group Management Protocol) is a session-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.