Nmap (“Network Mapper”) is a free and open source (license) utility for network discovery and security auditing. Many systems and network administrators also find it useful for tasks such as network inventory, managing service upgrade schedules, and monitoring host or service uptime.

In this article, we’ll do network scan with Nmap. By default, it is available on Kali Linux and Parrot OS. If you need to install it manually you can follow this article.

Table of Contents

1. Run Simple Scan
2. Perform a Fast Scan
3. Scan a Specific Port
4. Scan Top Ports
5. Find Open Ports
6. Detect OS
7. Aggressive OS Detection
8. Save Results

Run Simple Scan

Let’s run a simple scan:

nmap scanme.nmap.org

Perform a Fast Scan

Using parameter -F, we can perform a fast scan:

nmap -F scanme.nmap.org

Scan a Specific Port

To run a specific port scan parameter -p is used.

nmap -p 80 scanme.nmap.org

Scan Top Ports

Using parameter –top-ports we can scan many top ports at once:

nmap --top-ports 5 scanme.nmap.org

Find Open Ports

Just use –open parameter to show find open ports:

nmap --open scanme.nmap.org

Detect OS

Detect server’s operating system (OS):

nmap -O scanme.nmap.org

Aggressive OS Detection

Run this command to get aggressive OS detection results:

nmap -sV --version-intensity 5 scanme.nmap.org

Save Results

To save a scan output in a text file, use -oN parameter:

nmap -oN results.txt scanme.nmap.org