Concentrating on Linux installation, tuning, and administration, this guide to protecting systems from security attacks demonstrates how to install Linux so that it is tuned for the highest security and best performance, how to scan the network and encrypt the traffic for securing all private traffics in a public network, and how to monitor and log the system to detect potential security problems. Backup and recovery policies that provide a structure for secure operations are also considered, and information related to configuring an Apache server, e-mail service, and the Internet gateway using a proxy server, an FTP server, DSN server for mapping DNS names to IP addresses, and firewall for system protection is provided.
This book is devoted to exploring one of the most popular operating systems installed on servers: Linux. So far, this operating system has not been as popular among home users as among professional administrators. There have been, however, developments of late that make this system likely to capture a good segment of the home-computer operating system market. The operating system is becoming easier to install all the time, and its graphical user interface and the ease of use often give the most popular operating system among home users — Windows — a good run for its money.
This book will be of use to Linux administrators and to those Linux users who want to learn this operating system in more detail. The discussion of the configuration and security issues will come in handy for network security professionals, even those running other operating systems, because the larger part of the information is not tied to any specific operating system.
You will learn how hackers break into servers, and use the knowledge to prevent them from breaking into your server. Because some examples provided in the book can be used not only for defense but also for offense, I would like to give fair warning to young aspiring hackers. Curiosity is a commendable quality, but remember that the law is ever vigilant and always gets its man. If you get away with one break-in, next time you may not be so lucky and may have to spend some time in a company of unfortunate specimens of humankind, where your hacking skills will be of little use to you.
Some material in the book is presented from the hacker's point of view and describes methods of breaking into computer systems. I hope that this information will not actually be put to use. But being somewhat skeptical of the average human integrity, I tried to place more emphasis on defense against breaking in. I also left out some aspects and gave only a general description of others in order not to lead you into the temptation of applying these methods in practice.
You only need to spend a few minutes on programming or on Internet research to finalize my thoughts. Although this book can serve as a starting point for learning break-in techniques, I hope you will not use the acquired knowledge maliciously. If common morality is not enough to keep you from stepping onto the slippery path of computer burglary, remember the legal ramifications of your actions.
