- Freecom Router User Manual

Freecom FSG-3 Storage Gateway
GB
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Domain Name Server
Since this computer address is not very easy to read, there is a second system on
the internet called DNS (Domain Name System) which translates human read-
able names such as "www.sharemydisk.com" to computer readable names such
as "82.161.11.206". Everyone on the internet must have an IP address. You don’t
need the human readable name, but it helps tremendously if you want others
to find you, such as the case when you have a web server running or want to show
the pictures on your computer to your friends.
Many large organizations, such as ISPs, maintain their own DNS servers and allow
their customers to use the servers to look up addresses.
The internet address classes
Blocks of addresses are assigned to organizations by the Internet Assigned
Numbers Authority (IANA). Individual users and small organizations may obtain
their addresses either from the IANA or from an Internet service provider (ISP).
You can contact IANA at www.iana.org.
The IANA gives out ranges of IP addresses based on classes. There are five
standard classes of IP addresses. The five address classes 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 can have 254 hosts on a network. Class C addresses use 24 bits
for the network address and eight bits for the node. They are in this range:
192.0.1.x to 223.255.254.x.
Class D
Class D addresses are used for multicasts (messages sent to many hosts). Class D
addresses are in this range:
224.0.0.0 to 239.255.255.255.