The Daybo Logic CIDR Calculator

Last update: 23rd April 2003


CIDR 0.3.0
Author: David Duncan Ross Palmer
License: BSD
This is not the CIDR which comes pre-installed with FreeBSD

The CIDR utility is a small utility which can be used at the command line for determining from a given start IP address, end IP address and submask, what a given CIDR notation should be. For example, we all know that 192.168.0.0 - 192.168.0.255 is 192.168.0.0/24, however, it becomes harder when we break outside of the old fashioned and well known A, B and C class networks and wants to use true classless inter-domain routing. The utility uses no socket functions and should compile on nearly anything you want to throw at it. Please let me know if you find any bugs or discrepancies.

DOWNLOAD   <-- Grab source here.
Bitbucket repository

Known problems with this release. The calculation only works one way, unfortunately it does not yet produce the start, end and mask for a given CIDR-notation netblock.