Introduction

Here is a small tip on how to determine OS of the remote computer using nmap command. This can be quite handy if you are trying to create inventory list of your LAN hosts or you simply do not know what is running behind certain local or remote IP address and you need some hints. Using nmap for this kind of job does not mean that you will be able to identify remote OS with 100% accuracy but nmap will certainly provide you with some quite solid educated guess.

Simply, scan of a local network

When trying to determine OS of the remote host using nmap, nmap will base its guess on various aspects such as open and closed ports of default OS installation, operating system fingerprints already submitted to nmap database by other users, MAC address etc.