Nmap, or network mapper, is a command built into kali linux. It allows you to see connected devices to a network which is highly important for keeping a network secure.

How to use nmap

• sudo nmap -sS < ip address >

nmap can be used without sudo but in order to utilize the more advanced features you need root access. You can give nmap root access by adding sudo in front of the command.

• nmap has different tags available other than -sS

  -O enables OS detection (you can see what operating system devices are on)

  -sT uses TCP which requires 3 way handshake

  -sS doesn't actually connect with server (does not send ack packet back)

  -A incorporates multiple commands into one. OS detection, version detection, script scanning and traceroute.

  -list of all tags