IP address - Internet Protocol (IP) address

IP address is short for
Internet Protocol ( IP)
address.
IP specifies the
format of packets , also
called datagrams, and
the addressing scheme.
An IP address is an
identifier for a computer or device on a
TCP/IP network. Networks using the TCP/
IP protocol route messages based on the
IP address of the destination.

The Format of an IP Address

The format of an IP address is a 32-bit numeric
address written as four numbers separated by
periods. Each number can be zero to 255. For
example, 1.160.10.240 could be an IP address.
Within an isolated network, you can assign IP
addresses at random as long as each one is
unique. However, connecting a private network
to the Internet requires using registered IP
addresses (called Internet addresses) to avoid
duplicates.
Static Versus Dynamic IP Addresses
An IP address can be static or dynamic. A static
IP address will never change and it is a
permanent Internet address. A dynamic IP
address is a temporary address that is assigned
each time a computer or device accesses the
Internet.
The four numbers in an IP address are used in
different ways to identify a particular network
and a host on that network. Four regional
Internet registries -- ARIN , RIPE NCC, LACNIC
and APNIC-- assign Internet addresses from the
following three classes:
Class A - supports 16 million hosts on
each of 126 networks
Class B - supports 65,000 hosts on each of
16,000 networks
Class C - supports 254 hosts on each of 2
million networks
The number of unassigned Internet addresses is
running out, so a new classless scheme called
CIDR is gradually replacing the system based on
classes A, B, and C and is tied to adoption of
IPv6 . In IPv6 the IP address size is increased
from 32 bits to 128 bits.
What is My IP Address?
To view your IP address you can use the ipconfig
(IPCONFIG) command line tool. Ipconfig
displays all current TCP/IP network configuration
values and refreshes Dynamic Host Configuration
Protocol ( DHCP ) and Domain Name System
( DNS ) settings.
To launch the command prompt from a
Windows-based computer click: Start > All
Programs > Accessories > Command Prompt.
Type ipconfig and press the Enter key.
You can also use Google search to find your IP
address. Type " what is my IP address" as a
search query and Google will show the IP
address of the computer from which the query
was received as the top search result.