IPv4 Address Block

Published on April 3rd, 2014

a contiguous block of Internet Protocol Version 4 Numbers, commonly expressed as a Classless Inter-Domain Routing notation, e.g., A.B.C.D/X, where A, B, C and D are numbers between 0 and 255 (inclusive) and X is a number between 0 and 32 (inclusive).

CIDR Notation Number of Hosts Number of Classes Example Range
x.y.z.0/24 256 1 C to
x.y.z.0/16 65,536 1 B = 256 C to
x.y.z.0/8 16,777,216 1 A = 256 B to