Exim delivers electronic mail, both local and remote. It has all the virtues of a good postman: it's easy to talk to, reliable, efficient, and eager to accommodate even the most complex special requests. It's the default mail transport agent installed on some Linux systems, runs on many versions of Unix, and is suitable for any TCP/IP network with any combination of hosts and end-user mail software.Exim is growing in popularity because it is open source, scalable, and rich in features such as the following: Compatibility with the calling interfaces and options of Sendmail (for which Exim is usually a drop-in replacement) Lookups in LDAP servers, MySQL and PostgreSQL databases, and NIS or NIS+ services Support for many kinds of address parsing, including regular expressions that are compatible with Perl 5 Sophisticated error handling Innumerable tuning parameters for improving performance and handling enormous volumes of mail Best of all, Exim is easy to configure. You never have to deal with ruleset 3 or worry that a misplaced asterisk will cause an inadvertent mail bomb.While a basic configuration is easy to read and can be created quickly, Exim's syntax and behavior do get more subtle as you enter complicated areas like virtual hosting, filtering, and automatic replies. This book is a comprehensive survey that provides quick information for people in a hurry as well as thorough coverage of more advanced material.

This book is designed as an Ubuntu 21.04 Server administration and reference source, covering the Ubuntu servers and their support applications. Server tools are covered as well as the underlying configuration files and system implementations. The emphasis is on what administrators will need to know to perform key server support and management tasks. Coverage of the systemd service management system is integrated into the book. Topics covered include software management, systemd service management, AppArmor security, OpenSSH, the Chrony time server, and Ubuntu cloud services. Key servers are examined, including Web, FTP, CUPS printing, NFS, and Samba Windows shares. Network support servers and applications covered include the Squid proxy server, the Domain Name System (BIND) server, DHCP, distributed network file systems, IPtables firewalls, and cloud computing.

Linux deployment continues to increase, and so does the demand for qualified and certified Linux system administrators. If you're seeking a job-based certification from the Linux Professional Institute (LPI), this updated guide will help you prepare for the technically challenging LPIC Level 1 Exams 101 and 102. The third edition of this book is a meticulously researched reference to these exams, written by trainers who work closely with LPI. You'll find an overview of each exam, a summary of the core skills you need, review questions and exercises, as well as a study guide, a practice test, and hints to help you focus. Major topics include: Critical GNU and Unix commands Linux installation and package management Devices and filesystems Text editing, processing, and printing The X Window System Networking and security Mail transfer agents Email, FTP, and web services These exams are for junior to mid-level Linux administrators with about two years of practical system administration experience. You should be comfortable with Linux at the command line and capable of performing simple tasks, including system installation and troubleshooting.

Here are all the CompTIA Linux+/LPIC-1 Linux commands you need in one condensed, portable resource. The CompTIA Linux+/LPIC-1 Portable Command Guide is filled with valuable, easy-to-access information and is portable enough to use wherever your work takes you. The guide summarizes all Linux+/LPIC-1 certification-level Linux commands, keywords, command arguments, and associated prompts, and provides tips and examples of how to apply them to real-world scenarios. Configuration examples throughout the book provide you with a better understanding of how these commands are used in real-world environments. This book reflects topics in today’s CompTIA LX0-103 & LX0-104 and LPI 101-400 & 102-400 exams. Use this quick reference resource to help you memorize commands and concepts as you work to pass any of these CompTIA or LPI certification exams. The book is organized into these parts: Exam LX0-103/LPI 101-400 Part I: System Architecture Part II: Linux Installation and Package Management Part III: GNU and Unix Commands Part IV: Devices, Linux Filesystems, Filesystem Hierarchy Standard Exam LX0-104/LPI 102-400 Part V: Shells, Scripting, and Data Management Part VI: User Interfaces and Desktops Part VII: Administrative Tasks Part VIII: Essential System Services Part IX: Networking Fundamentals Part X: Securityuick, offline access to all CompTIA Linux+/LPI LPIC-1 commands for research and solutions Logical how-to topic groupings for a one-stop resource Great for review before your Linux+ or LPIC-1 certification exams Compact size makes it easy to carry with you, wherever you go “Create Your Own Journal” appendix with blank, lined pages allows you to personalize the book for your needs “What Do You Want to Do?” chart inside front cover helps you to quickly reference specific tasks

A guide to the Debian 2.1 distribution of Linux demonstrates the capabilities of the completely open-source operating system, covering installation, setup, and basic applications

Linux consistently turns up high in the list of popular Internet servers, whether it's for the Web, anonymous FTP, or general services like DNS and routing mail. But security is uppermost on the mind of anyone providing such a service. Any server experiences casual probe attempts dozens of time a day, and serious break-in attempts with some frequency as well. As the cost of broadband and other high-speed Internet connectivity has gone down, and its availability has increased, more Linux users are providing or considering providing Internet services such as HTTP, Anonymous FTP, etc., to the world at large. At the same time, some important, powerful, and popular Open Source tools have emerged and rapidly matured--some of which rival expensive commercial equivalents--making Linux a particularly appropriate platform for providing secure Internet services. Building Secure Servers with Linux will help you master the principles of reliable system and network security by combining practical advice with a firm knowledge of the technical tools needed to ensure security. The book focuses on the most common use of Linux--as a hub offering services to an organization or the larger Internet--and shows readers how to harden their hosts against attacks. Author Mick Bauer, a security consultant, network architect, and lead author of the popular Paranoid Penguin column in Linux Journal, carefully outlines the security risks, defines precautions that can minimize those risks, and offers recipes for robust security. The book does not cover firewalls, but covers the more common situation where an organization protects its hub using other systems as firewalls, often proprietary firewalls. The book includes: Precise directions for securing common services, including the Web, mail, DNS, and file transfer. Ancillary tasks, such as hardening Linux, using SSH and certificates for tunneling, and using iptables for firewalling. Basic installation of intrusion detection tools. Writing for Linux users with little security expertise, the author explains security concepts and techniques in clear language, beginning with the fundamentals. Building Secure Servers with Linux provides a unique balance of "big picture" principles that transcend specific software packages and version numbers, and very clear procedures on securing some of those software packages. An all-inclusive resource for Linux users who wish to harden their systems, the book covers general security as well as key services such as DNS, the Apache Web server, mail, file transfer, and secure shell. With this book in hand, you'll have everything you need to ensure robust security of your Linux system.

The definitive guide to the basics of one of the most popular operating systems in the world Whether you're a first-time Linux user or you're migrating from another operating system, this book is an ideal introductory guide for getting comfortable with the building-block nature of Linux. Written by bestselling author Christopher Negus, this guide is packed with in-depth descriptions on the basics of Linux desktops, servers, and programming tools and gets you up to speed on all the new and exciting features of the newest version: Linux 2010. Negus walks you through transitioning from Windows or Mac and helps you find the Linux distribution that best meets your needs. You'll explore more than 18 Linux distributions, including the latest versions of Ubuntu, Fedora, Debian, OpenSUSE, Slackware, Knoppix, Gentoo, Mandriva, SLAX, and more. Plus, you'll discover how to set up secure, fully functioning Linux server systems and get up-to-date installation advice. Topics Covered: Getting off the Ground with Linux Running a Linux Desktop Learning System Administration Skills Setting Up Linux Servers Choosing and Installing Different Linux Distributions Programming in Linux Linux Bible 2010 Edition walks you through the details of the various Linux distributions and updates you on the latest networking, desktop, and server enhancements. Note: CD-ROM/DVD and other supplementary materials are not included as part of eBook file.

The most up-to-date guide on the latest version of Linux Linux is an excellent, low-cost alternative to more expensive operating systems and its popularity continues to remain on the rise. This comprehensive resource offers more than 100 pages of the most sought-after Linux commands, provides new tutorial chapters aimed specifically at Windows desktop users and Windows administrators, and includes a new chapter on using Linux on gadgets. You’ll get up to speed with Linux so that you can install secure, fully functioning Linux server systems. Shows you what Linux is capable of, how to install it, how to make the most of its features, and ways to make use of its commands Provides step-by-step instructions for transitioning to Linux and explains how to choose which distribution is right for you, find and use the applications you need, set up the desktop to be the way you like it, and more Walks you through transferring your stuff (music, documents, and images) from Windows to Linux Whether you're making the transition from Windows or Macintosh and need to choose which distribution is right for you or you are already savvy with Linux and need a thoroughly up-to-date guide on its newest features, Linux Bible 2011 Edition is a must have!

This book is a practical guide to IPv6 addressing Unix and network administrators with experience in TCP/IP(v4) but not necessarily any IPv6 knowledge. It focuses on reliable and efficient operation of IPv6 implementations available today rather than on protocol specifications. Consequently, it covers the essential concepts, using instructive and thoroughly tested examples, on how to configure, administrate, and debug IPv6 setups. These foundations are complemented by discussions of best practices and strategic considerations aimed at overall efficiency, reliability, maintainability, and interoperation.