* [grml](https://grml.org) – bootable Debian Live CD with powerful CLI tools.
* [mitmproxy](http://mitmproxy.org/) - A Python tool used for intercepting, viewing and modifying network traffic. Invaluable in troubleshooting certain problems.
* [mtr](https://www.bitwizard.nl/mtr/) - Network utility that combines traceroute and ping.