IP
1.
Short for Internet Protocol address, an IP or IP address
is a number (example shown above) used to indicate the location of a computer
or other device on a network using TCP/IP.
These addresses are similar to those of your house; they allow data to reach
the appropriate destination on a network and the Internet.
There
are five classes of available IP ranges: Class A, Class B, Class C, Class D and
Class E, while only A, B, and C are commonly used. Each class allows for a
range of valid IP addresses, shown in the following table.
Class
|
Address Range
|
Supports
|
Class
A
|
1.0.0.1
to 126.255.255.254
|
Supports
16 million hosts on each of 127 networks.
|
Class
B
|
128.1.0.1
to 191.255.255.254
|
Supports
65,000 hosts on each of 16,000 networks.
|
Class
C
|
192.0.1.1
to 223.255.254.254
|
Supports
254 hosts on each of 2 million networks.
|
Class
D
|
224.0.0.0
to 239.255.255.255
|
Reserved
for multicast groups.
|
Class
E
|
240.0.0.0
to 254.255.255.254
|
Reserved
for future use, or Research and Development Purposes.
|
Ranges
127.x.x.x are reserved for the loopback or localhost, for example, 127.0.0.1 is the
common loopback address. Range 255.255.255.255 broadcasts to all hosts on the local network.
IP address breakdown
Every
IP address is broken down into four sets of octets
and translated into binary to represent the actual IP address. The below table is
an example of the IP 255.255.255.255. If you are new to binary, we highly
recommend reading our binary and hexadecimal conversions section to get a better
understanding of what we're doing in the below charts.
IP:
|
255
|
255
|
255
|
255
|
Binary
value:
|
11111111
|
11111111
|
11111111
|
11111111
|
Octet
value:
|
8
|
8
|
8
|
8
|
For
an example, let's break down the IP "166.70.10.23" in the following
table. The first row contains the separate sections of the IP address, the
second has binary values, and the third row shows how the binary value equals
the section of the IP address.
IP:
|
166
|
70
|
10
|
23
|
Binary
value:
|
10100110
|
01000110
|
00001010
|
00010111
|
Numerical
value:
|
128+32+4+2=166
|
64+4+2=70
|
8+2=10
|
16+4+2+1=23
|
Automatically assigned addresses
There
are several IP addresses that are automatically assigned when you set up a home
network. These default addresses are what allow your computer and other network
devices to communicate and broadcast information over your network. Below are
the most commonly assigned default addresses for home networks.
192.168.1.0
|
0
is the automatically assigned network address.
|
192.168.1.1
|
1
is the commonly used address used as the gateway.
|
192.168.1.2
|
2
is also a commonly used address used for a gateway.
|
192.168.1.3
- 254
|
Addresses
beyond 3 are assigned to computers and devices on the network.
|
192.168.1.255
|
255
is automatically assigned on most networks as the broadcast address.
|
If
you have ever connected to your home network, you should be familiar with the
gateway address or 192.168.1.1, which is the address you use to connect to your
home network router to change its settings.
Getting an IP address
By
default the router you use will assign each of your computers their own IP
address, often using NAT to forward the data coming from those computers to outside
networks such as the Internet. If you need to register an IP address that can
be seen on the Internet, you must register through InterNIC or use a web host
that can assign you addresses.
Anyone
who connects to the Internet is assigned an IP address by their Internet
Service Provider (ISP), which has registered a range of IP addresses. For
example, let's assume your ISP is given 100 addresses, 109.145.93.150-250. In
this range, the ISP owns addresses 109.145.93.150 to 109.145.93.250 and can
assign any address in that range to its customers. So, all these addresses
belong to your ISP until they are assigned to a customers computer. In the case
of a dial-up connection, you are given a new IP address each time
you dial into your ISP. With most broadband Internet service providers, you are always connected
to the Internet your address rarely changes. It remains the same until the
service provider requires otherwise.
