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

Configuring a console for debugging using Netconsole


If we want to capture a kernel panic, it becomes hard once the system has been rebooted as there are no logs created for this. To solve this issue, we can use Netconsole.

A kernel module helps by logging kernel print messages over UDP. This becomes helpful with debugging problems when logging on to the disk fails.

Getting ready

Before starting the configuration of Netconsole, we need to know the MAC address of the system where the UDP packets will be sent. This system is referred to as a receiver, and it may be in the same subnet or a different one. These two cases are described here:

  1. The first case is when the receiver is in the same subnet.

  2. The IP address of the receiver in this example is 192.168.1.4. We will send UDP packets to this IP address.

  3. Now, let's find the MAC address of the receiver system by executing this command. In the following case, the IP address is of the receiver system.

    As we can see in the preceding example, 90:00:4e:2f...