User's Manual

Wireless-G Router User's Manual
Each number in an IP address takes up an octet — eight bits — of computer storage
space, so its range is 0–255. Certain numbers, however, have special significance in
certain positions. No machine's IP address can end in 0 or 255, for example.
Subnet Mask: Each machine on an IP network must have an IP address that is unique
on that network. All the machines, however, must share a set of values called a subnet
mask. The router's default LAN-side subnet mask is 255.255.255.0. Combined with
the router's default LAN-side IP address of 192.168.1.1, this tells us (and all machines
getting their IP settings from the router) —
• The first three numbers of the IP address — 192.168.1 — are the network portion
of the address, shared by all machines on the LAN, and the fourth number is the
host portion, unique to each machine.
• The machines on the LAN (including the router) can have.IP addresses from
192.168.1.1 to 192.168.1.254. Machines with addresses in this range are local,
and can be reached directly.
• Machines with IP addresses outside this range can only be reached through a
gateway such as the router.
DNS: We prefer names to IP addresses. The name www.bigcompany.com is likely to
identify a Web server in the domain of servers run by bigcompany, which is part of
the domain of commercial enterprises on the Internet. To reach this server, we need its
IP address. Our Internet software gets the address by contacting a Domain Name
System (DNS) server, also called a name server. If one DNS server doesn't have a
particular IP address in its tables, it can get it from a DNS server that does.
The IP address of at least one DNS server is a required setting for any machine that
will access the Internet. On most types of Internet connections, the router can get at
least one DNS server's IP address from your ISP, and it passes the address(es) to
machines on the LAN that get their IP settings from the router.
MAC Address: Ethernet was developed separately from the Internet and has a very
different system of addressing. In Ethernet, each device is identified by its medium (or
media) access control (MAC) address. This is a value that is assigned at the factory
and usually cannot be changed. The Institute of Electrical and Electronics Engineers
(IEEE) administers a system that ensures that no two Ethernet devices in the world
have the same MAC address.
A device's MAC address is usually printed on a sticker placed on the back or bottom
of the device. Various formats are used, but the address is always in hexadecimal
(base 16) notation and always consists of twelve hexadecimal digits. Two common
formats are 12:34:56:78:9A:BC and 123456:789ABC .
5