122
Freecom Storage Gateway (FSG)
GB
This serves the same basic function as a street address. It helps you find out where you
currently are, while also providing other information. The IP address consists of four
numbers between 0 and 255 (e.g., 192.168.0.12).
Domain Name Server
The computer address is difficult to read, which is why a second system is used in the
Internet by the name of DNS (Domain Name Server). This translates human-readable
names such as www.sharemydisk.com into computer readable names like 82.161.11.206.
Each Internet user must have an IP address. You do not need the human-readable name,
but it is quite useful if you want other users to find you. A few examples of this include:
if you operate a web server or if you want to show your friends images stored on your
computer. Many large companies such as ISPs maintain their own DNS server and let
their customers use the server to search for addresses.
Internet address classes
The Internet Assigned Numbers Authority (IANA) allocates certain blocks of addresses to
organizations. Individual users or small organizations can obtain their addresses either
from the IANA or from an Internet service provider (ISP). You can visit the IANA homepage
at www.iana.org. The IANA issues different class of IP addresses. There are five standard
classes of IP addresses. They are:
Class A
Class A addresses can have up to 16,777,214 hosts on a single network. They use an eight-
bit network number and a 24-bit node number. Class A addresses are in this range: 1.x.x.x
to 126.x.x.x.
Class B
Class B addresses can have up to 65,354 hosts on a network. A Class B address uses a 16-
bit network number and a 16-bit node number. Class B addresses are in this range:
128.1.x.x to 191.254.x.x.
Class C
Class C addresses may have up to 254 hosts in one network. Class C addresses use 24 bits
for network addresses and eight bits for nodes. They range from 192.0.1x to 223.255.254.x.
