ip-checker

A simple tool to confirm/deny that a given IP address falls within a given CIDR.

Description

As IP address spaces are rather large (IPv6 is ridiculously over-sized), iteration over a given CIDR is neither efficient nor even feasible in some cases. Instead, we reduce this problem to a matter of simple, fast arithmetic checks, just as nature intended.

Basic features:

• Compatible with IPv4 or IPv6 inputs (will auto-detect, even).
• Will return (standard) exit values of '0' if true/success or '1' if false/fail.
• Silent mode will give no output, yielding only exit codes.
• Intended for easy inclusion into other scripting frameworks and worflows.

All source code is written for clarity and maintainability and should be mostly self-explanatory.

Prerequisites

Requires Python 3.x (preferably 3.7+) and uses the following (entirely standard) libraries:

• sys
• ipaddress
• argparse

Example Usage and Notes

Options:

usage: ip-checker.py [-h] -c CIDR -a ADDR [-s]

options:
  -h, --help            show this help message and exit
  -c CIDR, --cidr CIDR  CIDR against which to test
  -a ADDR, --addr ADDR  IP address to evaluate
  -s, --silent          Silent output mode

Checking IPv6 Addresses:

# ./ip-checker.py --cidr "2c0f:f248::/32" --addr "2c0f:f248:ffff:ffff:ffff:ffff:ffff:abcd; echo $?;"
Address is within CIDR
0

Note: As IPV6 addressing can use more flexible notation, this has been included as a feature. Use of both 'exploded' and 'compressed' formats are acceptible.

Checking IPv4 Addresses":

# ./ip-checker.py --cidr "192.168.1.0/24" --addr "192.168.2.5"; echo $?;
Address is NOT within CIDR
1

Note: Use "silent mode" will return only an exit value without output to stdout.

License

This tool is released under the MIT license. See the LICENSE file in this repo for details.

Built With

• Python designed by Guido van Rossum

Author

Rick Pelletier - Gannett Co., Inc. (USA Today Network)