IPv4 Calculator Subnetting / V

It is a tool for professionals and students of IT, which allows to use two different techniques for the division of subnets, Subnetting and VLSM, the data provided for each new subnet is, the network address, the first and the last host, the address of broadcast and the subnet mask.
It is able to store the results in a local database, and to export the calculations in a file with extension .xls