ipala

IP Address List Aggregator

Introduction

This command line utility takes a list of ip addresses and/or networks / subnets from stdin and prints an aggregated list to stdout that no longer contains ip addresses that are part of a network that is on the same list. The same goes for networks / subnets that are part of a larger network / subnet

Both IPv4 and IPv6 are supported.

IP networks / subnets need to be in CIDR notation (please see RFC2317).

Building and dependencies

ipala is written in Go (Golang), Go SDK v1.20+ is required. You can either run go build or go for a platform build:

• make amd64 for x86_64
• make arm64 for arm64

Usage

Let's jump into an example:

A file example.txt contains the following lines:

10.1.1.1
10.1.1.0/24
10.1.0.0/16
192.168.1.0/24
192.168.2.0/24
192.168.1.1
192.168.2.1
192.168.3.1

If you cat example.txt | ipala you get the following list:

10.1.0.0/16
192.168.1.0/24
192.168.2.0/24
192.168.3.1

All three single ip addresses 10.1.1.1, 192.168.1.1, and 192.168.2.1 that are part of a network that is also listed are gone, so is the network / subnet 10.1.1.1.0/24 that is part of the larger network / subnet 10.1.0.0/16.

FAQ

• Do we really need a new tool? Isn't it easier and more flexible to use regex and a small script to achieve the same results? Yes and no. Regex (regular expressions) may work in most cases, but things get a bit messy when it comes to debugging or when you have to deal with ip addresses in CIDR notation (/32 for IPv4, /128 for IPv6),
• Where is this tool used? We use this tool in our pipelines to optimise e.g. our Threat Data Feeds for SOHO. These feeds contain known spambots, forum spammers, ip scanners, etc. that should be blocked at the WAN side of a network. The problem with SOHO (small office home office) network equipment is that it is notoriously low on CPU power and RAM, so smaller more optimised lists are key for a successful deployment on these kind of devices.

Feedback

We would love to hear from you! Please contact us at [email protected] for feedback and general requests. Kindly raise an issue in GitHub if you find a problem in the code.

License

Release under the MIT License. (see LICENSE)

QA