Projects / Whatmask


Whatmask is a small C program that helps with network settings. Notations supported are CIDR (e.g. /24), Netmask (e.g., and Wilcard Bits (e.g. These notations are all identical. CIDR notation commonly has a "/" in front of the number (representing the number of bits). Whatmask can accept these notations with or without a slash. It can take any IP in the subnet along with the netmask in any format, and it will echo back the netmask in three formats, the network address, the broadcast address, the number of useable IPs, and the range of IPs in the subnet. Binaries for Linux, Win32, and MacOS 9/X are available.

Operating Systems

Recent releases

  •  26 Sep 2001 17:53

    Release Notes: Support for reporting network address, broadcast address, number of usable IPs in the subnet, and the IP range, general code cleanups, and binaries for Linux, Win32, and MacOS.

    •  19 May 2001 07:07

      Release Notes: Initial Release


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