Taming the TerminalI’ve not been happy with any of the free subnet calculators I’ve found online, and that came to a head when I was looking for something I could feel happy recommending within the Taming the Terminal series. The great thing about being able to code is that you can scratch your own itch!

The calculator I’ve written is primarily designed around expanding out the network information users will find in the Windows Control Panel, OS X System Preferences, or from terminal commands like ipconfig (Windows) and ifconfig (Linux, Unix, OS X). It’s not realistic to expect users to convert netmasks from one notation to another, so the calculator is very liberal in the netmasks it accepts.

The secondary audience for the calculator is students and anyone else interested in understanding the math behind IP subnets. To that end there is button that will expand the interface out to show the binary calculations being carried out under the hood.

Check it out at: www.SubnetCalc.it

This is a very new site, so I’m definitely open to constructive criticism, but please bear in mind the target audience is home users, not IT Pros, so I’m going to be very reluctant to follow through with any suggestions to add more complication to the interface.

I started this project by developing a set of JavaScript classes for representing and manipulating IP addresses, Netmasks, and IP Subnets. I’ve released that library under a BSD license over on my GitHub page – bartificer.ip.js.