Book Image

Practical Linux Security Cookbook

By : Michael A Lindner, Tajinder Kalsi
Book Image

Practical Linux Security Cookbook

By: Michael A Lindner, Tajinder Kalsi

Overview of this book

With the growing popularity of Linux, more and more administrators have started moving to the system to create networks or servers for any task. This also makes Linux the first choice for any attacker now. Due to the lack of information about security-related attacks, administrators now face issues in dealing with these attackers as quickly as possible. Learning about the different types of Linux security will help create a more secure Linux system. Whether you are new to Linux administration or experienced, this book will provide you with the skills to make systems more secure. With lots of step-by-step recipes, the book starts by introducing you to various threats to Linux systems. You then get to walk through customizing the Linux kernel and securing local files. Next you will move on to manage user authentication locally and remotely and also mitigate network attacks. Finally, you will learn to patch bash vulnerability and monitor system logs for security. With several screenshots in each example, the book will supply a great learning experience and help you create more secure Linux systems.
Table of Contents (17 chapters)
Practical Linux Security Cookbook
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

PortSentry


As a system administrator, one major concern is to protect the system from network intrusions.

This is where PortSentry comes into the picture. It has the ability to detect scans on a host system and react to those scans in the way we choose.

Getting Ready

To demonstrate the implementation and usage of PortSentry, we need two systems on the same network that can ping each other.

Also, we need the Nmap package on one system, which will be used as the client, and on the other system, we will install and configure the PortSentry package.

To install the Nmap package, use the following command:

apt-get install nmap

How to do it?

  1. On the first system, we install the Portsentry package, using the following command:

    apt-get install portsentry
    
  2. During the installation process a window will open containing some information about Portsentry. Just click OK to continue:

  3. As soon as the installation completes, portsentry starts monitoring on the TCP and UDP ports. We can verify this by checking the file...