How To Audit & Scan Security with NMAP in Linux
We show you how you can scan and audit the security of your Linux using the Nmap utility.
What is NMAP?
Nmap or also known as “Network Mapper”, is a free open source utility created to detect networks and perform security audits on network infrastructures.
Nmap was designed to scan large networks, but it works well against single hosts or small networks.
Step 1: Install Nmap on Linux
To install Nmap in our system, we can execute any of the following lines:
yum install nmap
Ubuntu – Debian
apt-get install nmap
Step 2: How to use Nmap
To understand all the options offered by nmap, we can run the next line:
The first option we have with nmap is to validate a website or an IP address, for this, we must execute the following line:
sudo nmap -sS [IP] or [website]
In this case, we will run the next line:
sudo nmap -sS www.solvetic.com
We can see in detail all the ports available on this website as well as its status and name of the service associated with that port.
Another option offered by nmap is to discover the operating system used by the website or the IP address that we indicate, for this, we must execute the following syntax:
sudo nmap -O --osscan-guess [IP] or [website]
The next alternative to use is to run a ping scan command which is practical when we must verify the open ports of a computer, in this case, we will use the following syntax:
sudo nmap -vv [IP] or [website]
Another available option is to check the services executed at the destination using the following syntax:
sudo nmap -sV [IP] or [website]
Thus we have seen how it is possible to use nmap to analyze in a much more complete way multiple aspects of the local or external network.