Book Image

Linux for System Administrators

By : Viorel Rudareanu, Daniil Baturin
Book Image

Linux for System Administrators

By: Viorel Rudareanu, Daniil Baturin

Overview of this book

Linux system administration is an essential aspect of maintaining and managing Linux servers within an organization. The role of a Linux system administrator is pivotal in ensuring the smooth functioning and security of these servers, making it a critical job function for any company that relies on Linux infrastructure. This book is a comprehensive guide designed to help you build a solid foundation in Linux system administration. It takes you from the fundamentals of Linux to more advanced topics, encompassing key areas such as Linux system installation, managing user accounts and filesystems, networking fundamentals, and Linux security techniques. Additionally, the book delves into the automation of applications and infrastructure using Chef, enabling you to streamline and optimize your operations. For both newcomers getting started with Linux and professionals looking to enhance their skills, this book is an invaluable hands-on guide with a structured approach and concise explanations that make it an effective resource for quickly acquiring and reinforcing Linux system administration skills. With the help of this Linux book, you’ll be able to navigate the world of Linux administration confidently to meet the demands of your role.
Table of Contents (21 chapters)
Part 1: Linux Basics
Part 2: Configuring and Modifying Linux Systems
Part 3: Linux as a Part of a Larger System

Routes and neighbor tables

To be able to communicate with other hosts over the network, it’s not enough for a host to have an address. It also needs to know how to reach other hosts. Modern networks use layered protocol stacks, and the Linux kernel is responsible for the Data Link and Network layers according to the OSI model.

At the data link layer, there are protocols such as Ethernet and Wi-Fi — both are multiple-access broadcast networks and require dynamic discovery of neighbors in the same network segment. At the data link layer, hosts are identified by their MAC addresses. Direct communication at the data link layer is only possible within the same segment. If a network layer protocol packet encapsulated in a data link layer protocol frame must travel further, it’s extracted from the original frame and encapsulated in a new one.

Above the data link layer are network layer protocols—IPv4 and IPv6. IP packets can be sent either to hosts in the...