Mastering Linux Security and Hardening - Second Edition

Auditing network services with Nmap

The netstat tool is very good, and it can give you lots of good information about what's going on with your network services. The slight downside is that you have to log in to every individual host on your network in order to use it. 

If you'd like to remotely audit your network to see what services are running on each computer, without having to log in to each and every one, then you need a tool such as Nmap. It's available for all the major operating systems, so even if you're stuck having to use Windows on your workstation, you're in luck. An up to date version is built into Kali Linux, if that's what you're using. It's also in the repositories of every major Linux distro, but the version that's in the ...