Interested in seeing what ports are open on your machine? Use NMAP to scan your machine or other machines on your network and figure out if there are any holes in your firewall or malicious software setting up camp. Particularly if you are moving a machine from a secure firewall to a less secure (required by a particular application for example), you could run NMAP and try to plug as many holes as possible before you expose this machine further.
NMAP works in Linux and Windows and comes with a handy GUI that is certainly simple enough or you can stick to the command prompt with a simple: nmap {hostname}
It’ll report what ports are open and what software is using it, like Remote Desktop, VNC, or other applications. Essential for the security toolbox.
