TCP/IP Calculator

The TCP/IP calculator is designed to assist users in validating a TCP/IP address and breaking the address into its various components (network, subnet and host) for display purposes.

Primarily, I wrote this function to show people the impact a subnet mask has on a TCP/IP address.

This program follows one basic rule, that being Neither the subnet or host portion of an address (in binary) can be all 1s or all 0s. In some vendors equipment, the use of subnet 0is allowed, however, being a "purist" I have taken what I consider to be a safer path. Subnetting with a subnet address of zero is generally not recommended because of the inherent confusion in having a network and a subnet with indistinguishable addresses. For example, if network 171.126.0.0 is subnetted as 255.255.255.0, subnet zero would be written as 171.126.0.0 which is identical to the network address. For this reason,I have programmed the calculator to mark such an address as an invalid address.

Upon entering a TCP/IP address and subnet mask, the program will convert both the address and mask into binary, colour code the binary bits according to network, subnetwork and host address. Network address bits are shown in red, Subnetwork bits are shown in blue and host bits are shown in yellow.

The calculator will break down the address and display the full network address and subnet address that the entered address is a part of. It will also display the subnet and host portion of the address. For each address entered, it will also display the broadcast address for the subnet that the entered address resides in.

A summary of the programs abilities is shown below:

- validate the address against the subnet mask
- convert the address and mask to binary
- highlight the binary bits that correspond to the network, subnet and host portion of the address
- colour code the binary bits according to the network, subnetwork and host portion of the addresses
- display the broadcast address for that network/subnetwork
- display the full network address
- display the full subnetwork address

NEW FUNCTION ADDED IN V3.11

With Version 3.11, I have added (at the request of many) the binary/decimal/hex calculator in the same window as the calculator.

Last Modified 12 August 1996 - Carl Solder