Book Image

Practical Linux Security Cookbook - Second Edition

By : Tajinder Kalsi
Book Image

Practical Linux Security Cookbook - Second Edition

By: Tajinder Kalsi

Overview of this book

Over the last few years, system security has gained a lot of momentum and software professionals are focusing heavily on it. Linux is often treated as a highly secure operating system. However, the reality is that Linux has its share of security ?aws, and these security ?aws allow attackers to get into your system and modify or even destroy your important data. But there’s no need to panic, since there are various mechanisms by which these ?aws can be removed, and this book will help you learn about different types of Linux security to create a more secure Linux system. With a step-by-step recipe approach, the book starts by introducing you to various threats to Linux systems. Then, this book will walk you through customizing the Linux kernel and securing local files. Next, you will move on to managing user authentication both locally and remotely and mitigating network attacks. Later, you will learn about application security and kernel vulnerabilities. You will also learn about patching Bash vulnerability, packet filtering, handling incidents, and monitoring system logs. Finally, you will learn about auditing using system services and performing vulnerability scanning on Linux. By the end of this book, you will be able to secure your Linux systems and create a robust environment.
Table of Contents (20 chapters)
Title Page
Copyright and Credits
Contributors
Packt Upsell
Preface
Index

Monitoring the network using Nmap


For any network, big or small, network monitoring and security is a very essential task. Regular monitoring of the network is important to protect the systems from attacks and also keeps viruses and malware out of the network.

Nmap, short forNetwork Mapper, is a free and open source tool for network monitoring and is the most versatile tool for system/network administrators. Nmap can be used to perform security scans, explore the network, find open ports on the remote system, and perform network audits.

 

Getting ready

To show you the workings of nmap, we need a minimum of two systems forming a small network. On one system, we will install the nmap package, while the other system will be used as a host to scan.

  1. To install nmap, if it is not already installed, run the following command:
  1. If we want to check the version of Nmap, we can use the following command:

How to do it...

In this section, we will see how we can use Nmap for performing different types of scans...