Computer Networks - Addressing Schemes (Class A, B, C, D, E)

1. Global Addresses

2. Global Addresses
- Used to uniquely identify the host globally.
- IP Addresses are hierarchical. i.e., it is made up of two parts,
o Network part
o Host part
- Totally it provides 4 billion addresses. In which,
o half are A type,
o ¼ is B type, and 1/8 is C type
- IP address is represented as Dot notation. Eg. 192.168.0.1

3. Global Addresses

4. Global Addresses
Class First Octet value Range No. of Network
No. of Hosts /
Network
A
00000000 – 01111111
(0 – 127)
1.0.0.1 –
126.255.255.254
126 224 - 2
B
10000000 – 10111111
(128 – 191)
128.1.0.1 –
191.255.255.254
16000 65000
C
11000000 – 11011111
(192 – 223)
192.0.1.1 –
223.255.255.254
2 Million 254
D
11100000 – 11101111
(224 – 239)
224.0.0.0 –
239.255.255.255
Multicast addresses
E
11110000 – 11111111
(240 – 255)
240.0.0.0 –
254.255.255.254
Future use
In class A 127.0.0.1 – 127.255.255.255 addresses are reserved for loopback &
diagnostic purpose.