Network Utilities tool made as a desktop application for Windows in order to learn about Windows Forms and C#, specifically some of the .NET framework and asynchronous utilities.
Subqueries generated by IP-range ping queries do not stop when the stop button is pressed - they are finished until completion on a target and wait for the subquery to stop before the IP-range query stops. This shouldn't be too difficult a fix, but I left it as a task to complete at a later date.