IP Audit

This is an excellent software for Linux users to track your incoming and outgoing (download and upload) data. It also warns you not to exceed your data limit when you enter it, and if you allow it, it blocks your internet connection after reaching that limit. You can also reset your data limit on a date you specify (e.g., at the beginning of each month). There's nothing better for Linux. If you don't want to use the beta version, you can download the latest stable version from their website. The program works on all Linux distributions. You can customize all the program's settings.