<%@LANGUAGE="JAVASCRIPT" CODEPAGE="1252"%> truter.biz - London news + IT in London + Lester Truter truter.biz Lester Truter; Business Objects;Lotus Notes; Domino; CLP :: IP Address Classes ::

 

Class A :

e.g. 10.1.2.3

16,777,214 hosts possible
The first byte of the four byte IP address identifies the network. The second, third and fourth bytes identify specific hosts.
i.e.
network = 10
host = 1.2.3

 

Class B:

e.g. 172.16.1.2

65,532 hosts possible
The first two bytes of the four byte IP address identifies the network. The third and fourth bytes identify specific hosts.
i.e.
network = 172.16
host = 1.2

 

Class C:

e.g. 192.168.1.2

254 hosts possible
The first three bytes of the four byte IP address identifies the network. The last byte identifies the specific hosts.
i.e.
network = 172.16
host = 1.2

Class A addresses have values in the first byte of : 1 - 127
Class B addresses have values in the first byte of : 128 - 191
Class C addresses have values in the first byte of : 192 - 223

 

The following classes are uncommon

 

Class D:

Multicast addresses - see RFC 1112

 

Class E:

Initial byte: 248 - 255

Reserved for experimental use