IP addressing

IPv4

• Network Address Range: Class A

0xxxxxxx
00000000 = 0
01111111 = 127

• Network Address Range: Class B

In a Class B network, the RFCs state that the first bit of the first byte must always be turned on but the second bit must always be turned off.
10000000 = 128
10111111 = 191

• Network Address Range: Class C

11000000 = 192
11011111 = 223

• Network Address Range: Class D

11100000 = 224
11101111 = 239

Reserved IP Address Space
Address Class                         Reserved Address Space
Class A                           10.0.0.0 through 10.255.255.255
Class B                           172.16.0.0 through 172.31.255.255
Class C                           192.168.0.0 through 192.168.255.255