IP Subnet Calculator

What?

The IP Subnet Calculator is a simple little utility that computes network masks and IP subnets of a network for easy provisioning. It is completely free with no strings attached. I will probably release it under the GPL at some point if I have enough requests for the source... The network masks are entered in CIDR format, which is supported by all major router and switch companies.

Why?

I haven't found a simple little utility to do subnetting that doesn't involve a web page or a mouse. If you're setting up subnets, you're probably connected to a router through telnet or ssh, so a command line utility makes perfect sense.

Where?

You may download the executable itself (184KB), a zip file containing the executable (90K), or a rar file containing the executable (78K) from this page.

There is now a linux binary (110K) available for those of you tired of Windows-only binaries.

Screenshots?

Well, as much as you can screenshot a console app :)

C:\temp>subnet 192.168.1.65/24 26
Showing        : 192.168.1.65/24     11000000.10101000.00000001.01000001

Subnet Mask    : 255.255.255.0       11111111.11111111.11111111.00000000
Wildcard Mask  : 0.0.0.255           00000000.00000000.00000000.11111111
Host Count     : 254

Network        : 192.168.1.0         11000000.10101000.00000001.00000000
Minimum Host   : 192.168.1.1         11000000.10101000.00000001.00000001
Maximum Host   : 192.168.1.254       11000000.10101000.00000001.11111110
Broadcast      : 192.168.1.255       11000000.10101000.00000001.11111111

/26 Subnets    : 4
Subnet Mask    : 255.255.255.192     11111111.11111111.11111111.11000000
Wildcard Mask  : 0.0.0.63            00000000.00000000.00000000.00111111
Host Count     : 62                  (Per Subnet)

Network        : 192.168.1.0         11000000.10101000.00000001.00000000
Minimum Host   : 192.168.1.1         11000000.10101000.00000001.00000001
Maximum Host   : 192.168.1.62        11000000.10101000.00000001.00111110
Broadcast      : 192.168.1.63        11000000.10101000.00000001.00111111

Network        : 192.168.1.64        11000000.10101000.00000001.01000000
Minimum Host   : 192.168.1.65        11000000.10101000.00000001.01000001
Maximum Host   : 192.168.1.126       11000000.10101000.00000001.01111110
Broadcast      : 192.168.1.127       11000000.10101000.00000001.01111111

Network        : 192.168.1.128       11000000.10101000.00000001.10000000
Minimum Host   : 192.168.1.129       11000000.10101000.00000001.10000001
Maximum Host   : 192.168.1.190       11000000.10101000.00000001.10111110
Broadcast      : 192.168.1.191       11000000.10101000.00000001.10111111

Network        : 192.168.1.192       11000000.10101000.00000001.11000000
Minimum Host   : 192.168.1.193       11000000.10101000.00000001.11000001
Maximum Host   : 192.168.1.254       11000000.10101000.00000001.11111110
Broadcast      : 192.168.1.255       11000000.10101000.00000001.11111111


C:\temp>

Changes?

Jan 31, 2006 - Successfully compiled a linux binary on Debian using g++ (Debian rocks)
Sep 22, 2005 - Fixed a bug that would cause a parse error on the IP address on some machines
Aug 7, 2005 - Added support for a /32 subnet mask for support of displaying a single IP address

Who?

My name is Eric Hill. You can reach me at e-r-i-c-@-i-j-a-c-k-.-n-e-t if you want.