Top 5 Linux Tools for Network Scanning

Network scanning is a critical function in the realm of system administration and cybersecurity. It helps in identifying active devices, discovering hosts, and unveiling vulnerabilities in the network. In this tutorial, we will explore the top 5 Linux tools for network scanning, suitable for both professionals and beginners.

Prerequisites

A Linux-based operating system (Ubuntu, CentOS, etc.).
Basic command line knowledge.
Root or sudo access to execute scanning tools.

1. Nmap

Nmap (Network Mapper) is one of the most widely used tools for network scanning. It allows users to discover hosts and services on a computer network by sending packets and analyzing the responses.

Installation

sudo apt install nmap  # For Debian-based systems
sudo yum install nmap  # For RedHat-based systems

Basic Usage

nmap   # Scan a single host
nmap /  # Scan a network

Example

nmap 192.168.1.1  # Scanning a specific IP address

2. Angry IP Scanner

Angry IP Scanner is a fast and easy-to-use IP address and network scanner. It’s open-source and cross-platform, making it a favorite among many administrators.

Installation

sudo apt install ipscan  # For Debian-based systems

Basic Usage

Run Angry IP Scanner from your applications menu or type ipscan in the terminal. Enter the desired IP range and start the scan.

3. Netcat

Netcat, often referred to as the “Swiss Army knife” of networking, can perform a variety of tasks, including network scanning.

Installation

sudo apt install netcat  # For Debian-based systems

Basic Usage

nc -zv  -  # Scan ports

Example

nc -zv 192.168.1.105 1-1000  # Scan the first 1000 ports

4. Masscan

Masscan is known for its speed and can scan the entire Internet in under 6 minutes, making it the fastest port scanner.

Installation

sudo apt install masscan  # For Debian-based systems

Basic Usage

masscan  -p  # Scan a specific port

5. Wireshark

Wireshark is a network protocol analyzer that enables users to capture and interactively browse traffic. It’s not a scanner per se, but it can help investigate active network traffic.

Installation

sudo apt install wireshark  # For Debian-based systems

Basic Usage

Run Wireshark from your applications menu and select the network interface to listen to; it will display all intercepted packets.

Troubleshooting Tips

Ensure you have the necessary permissions to run these tools.
Disable firewall rules that may block scanning.
Update the tools regularly to avoid compatibility issues.

Summary Checklist

Check for installation dependencies.
Run scans on the intended networks responsibly.
Document the findings for adequate follow-ups.

Network scanning is essential for maintaining a secure and efficient environment. For more insights on Linux tools, feel free to check our articles like Top 5 Linux Tools for System Administration.