How to get info from a LAN computer in Ubuntu

If we want to get information of a LAN device we should use the powerful tool nmap

To obtain data of the OS, see the MAC of the LAN device and check the open ports we should use the flag -O.

Let's supose the LAN device we want to check has the IP 192.168.0.20

#  To  execute  the nmap with -O flag we need to execute with sudo
sudo nmap -O 192.168.0.20


Starting Nmap 6.49BETA5 ( https://nmap.org ) at 2016-02-29 11:38 CET
Illegal character(s) in hostname -- replacing with '*'
Nmap scan report for gray* (192.168.0.20)
Host is up (0.0039s latency).
Not shown: 994 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
139/tcp  open  netbios-ssn
445/tcp  open  microsoft-ds
6881/tcp open  bittorrent-tracker
8080/tcp open  http-proxy
MAC Address: XX:XX:XX:XX:XX:XX (Asustek Computer)
Device type: general purpose
Running: Linux 3.X
OS CPE: cpe:/o:linux:linux_kernel:3
OS details: Linux 3.2 - 3.19
Network Distance: 1 hop