／var／logmarcus chiu

IPv4 - Address Classes (now obsolete)

Created on · Last Modified on

IP Address Classes
  • are hierarchical
  • contain 2 parts:
    • network prefix
      • identifies the network to which the host is attached to
      • con be coalesced into supernets (CIDR)
    • host suffix
      • identifies each host uniquely within the particular network
      • can be further split up into subnets
  • are separated into 5 classes (identified by the most significant bits)

IPv4 Address Classes (now obsolete)

Class

First Bits

IP Address Range

Description

A

0

0.X.X.X - 127.X.X.X

00000000.X.X.X - 01111111.X.X.X
  • 8-bits for network-prefix
  • 24 bits for host-suffix

B

10

128.X.X.X - 191.X.X.X

10000000.X.X.X - 10111111.X.X.X
  • 16-bits for network-prefix
  • 16 bits for host-suffix

C

110

192.X.X.X - 233.X.X.X

11000000.X.X.X - 11011111.X.X.X
  • 24-bits for network-prefix
  • 8 bits for host-suffix

D

1110

224.X.X.X - 239.X.X.X

11100000.X.X.X - 11101111.X.X.X
  • for multicast purposes

E

1111

240.X.X.X - 255.X.X.X

11110000.X.X.X - 11111111.X.X.X
  • for experimental purposes