Network OS: functions, types, various OS. Roderick Smith - Linux Networking Tools

Computer networks changed our lives. They were almost invisible in the 1970s and even in the 1980s. However, in the early 1990s, something happened. Perhaps it was the appearance of World Wide Web and graphical Web browsers, thanks to which the Internet came to many families. Perhaps the number network connections exceeded some critical limit. Maybe this limit has been exceeded by the number network programs. Be that as it may, now everyone knows about networks. And the most important thing is that everyone knows about the existence of the Internet.

The Internet connects millions of computers, many of which run servers - programs that receive requests from clients and process them. Due to the fact that the protocols on which the Internet is based allow cross-platform communication, clients and servers running on the Internet can participate in data exchange. various computers and in different operating environments. IN last years Linux has become one of the most popular operating systems. Installed on inexpensive computer x86, Linux system provides efficient work servers supporting small and medium sized nodes. As computer performance increases, it becomes possible to run in Linux servers, processing large volumes of data. As a result, a system administrator is often required to have the ability to configure a Linux system and the servers running in its environment.

Which servers should you choose? There are hundreds, if not thousands, server programs. In most books devoted to Linux system, the focus is on several popular servers: HTTP server (usually Apache), remote logging servers such as Telnet and SSH, file servers, examples of which are NFS and Samba, and some other types of servers. This book covers a wide variety of servers. The variety of issues under consideration does not make it possible to study in detail the operation and configuration features of each of the servers, but still the information provided is enough to ensure the implementation of the corresponding programs. In addition to the most popular servers, this book also covers tools that usually receive little attention, but which are nevertheless extremely important for normal functioning networks. For example, there are chapters on the DHCP server, the ephemeral server, and the Kerberos system. This book does not cover the basics of networking. It is assumed that the reader already has an understanding of network tools and is going to improve his skills.

The chapters that describe complex servers such as Apache and Samba do not cover them comprehensively. Behind general information These tools are followed by a discussion of their advanced features, aimed at an administrator with some experience. For beginners, before studying these chapters, it is advisable to read books containing an introductory course in administering these servers.

Who is this book for?

This book contains advanced information about Linux networking tools and is aimed at professionals who have already worked with networks and the Linux system. The first chapters provide information about setting up low-level Linux networking tools. To make sense of the material in these chapters, you need to have a basic understanding of Linux, or at least UNIX, and know the terminology used to describe networking tools. If you are not familiar with the Linux system, it makes sense for you to read introductory materials, for example, the book by Marcel Gagne Linux System Administration: A User's Guide(Addison-Wesley, 2002) or our book with Vicki Stanfield Linux System Administration(Sybex, 2001).

If you want to learn more about servers like Apache and Samba, but don't want to buy a book dedicated entirely to one product, or if you want to learn about small but very important servers, such as xntpd and xfs, this book is for you. In it you will also find numerous practical advice, for example, about how to start a server and shutdown it, how to create backup copy information on the network, how to limit the scope of the server to a subtree

, how to build a firewall, etc. This information will allow you to take a fresh look at the process of administering your network and, possibly, improve the performance and reliability of its operation.

In writing this book, I focused on administrators of small and medium-sized networks. Such a network may contain computers running UNIX, Windows, MacOS and other operating systems, and, of course, at least one Linux machine. Most chapters describe general principles the operation of a particular tool, and then provides information about its use. This book can be used as a reference guide. If you want to have a book that describes a wide variety of network Linux tools, then you hold it in your hands.

Linux versions

One of the reasons for problems when Linux administration is that Linux cannot be considered as a single operating system; it is rather a set of systems created on the basis of a single core. Varieties of Linux are called versions or distribution packages. The distribution package includes a kernel, an installation program aimed at this version Linux, a set of utilities, special tools, user programs, etc. In addition, any distribution package includes scripts; Some of them are designed for running servers, others for configuring system components. Different distribution packages contain different versions of the kernel and different sets of tools. When installing some distribution packages, they often install special servers, for example, a mail server, in the role of which, depending on Linux versions, programs are performed

, or Postfix. Character traits Each version of Linux leaves its mark on working with it and especially on its administration.

Many books ignore the differences between different versions Linux. They focus primarily on one distribution package, with others mentioned only occasionally. When writing this book, I set myself the goal of describing in more or less detail everything popular versions. In particular, it covers the features of Caldera OpenLinux 3.1, Debian GNU/Linux 2.2, Mandrake 8.1, Red Hat 7.2, Slackware 7.0, SuSE 7.3 and TurboLinux 7.0. I did not have the opportunity to examine each system in detail; I tried to draw the reader's attention to the main differences between them. For example, in the book you will find information about what tools are used in each version of Linux to run servers, what programs provide FTP interaction, etc. Some chapters discuss various programs, implementing specific type server. This is done so that you can get an idea of the differences in the default configuration in different distribution packages.

Book structure

The book consists of four parts, each containing from four to thirteen chapters. Servers used for maintenance local users, and the servers used to organize interaction over the Internet are described in different parts. However, it should be noted that some servers can be used for different purposes. The contents of each part are briefly described below.

Part I This part is shorter than the others; it contains only four chapters. It describes setting up the system kernel, provides general information about the configuration of TCP/IP tools, protocol stacks and startup scripts.

Part II. This part covers servers that will most likely only be accessed by computers on your local network. It discusses DHCP server, Kerberos system, Samba and NFS servers, LPD printing, ephemeral servers, POP and IMAP mail servers, news servers, remote login servers, X Window system and VNC server, font server, remote administration server and backup facilities.

Part III. This part is devoted to the consideration of servers used to work on the Internet. It provides information about DNS servers, mail servers, supporting SMTP protocol, Web and FTP servers.

Part IV. This part discusses issues network security. This covers general security issues, tools for creating a subtree

, setting special functions router, creating firewalls using , NAT tools and VPN setup. Conventions adopted in the book

To simplify the understanding of the material presented, the following conventions are adopted in the book.

The main text is displayed in a regular proportional font.

Italic terms that appear for the first time are presented. Additionally, italics are used to display text descriptions, replacing option values, record fields and other code fragments.

Monospace font

names of files and network hosts, fragments are highlighted program code, content configuration files, commands entered from the keyboard, and text displayed on the screen when the program runs.

If the text contains a command entered from the keyboard, a prompt is displayed at the beginning of the line. Symbol

indicates that the command is issued by the user (sometimes there are exceptions to of this rule). If the character appears as an input prompt, this means that the command is being entered regular user. Some commands may span multiple lines. An indication that the continuation of the command is on next line, is the symbol. You can enter the command exactly as it appears in the book, or you can skip the backslash and type the command on one line.

The book also contains special fragments of text that occupy one or more paragraphs. They contain information that is only indirectly related to the material presented, or, on the contrary, comments that should be noted Special attention. These fragments are highlighted as follows.

On a note
This is how information is presented that is not directly related to the issues discussed in the text, but may be useful to the reader. This could be, for example, information about the specifics of work earlier versions programs.

Advice
Data highlighted in this way will help you solve the problem in a non-obvious way. For example, a link to software, rarely mentioned in other sources.

Attention
This is how a warning is issued about the danger associated with certain actions. This could be, for example, information about programs that, if used incorrectly, can damage the system, recommendations to refrain from actions that do not comply with the provider's policy, or information about configuration features that can be used to illegally penetrate the system.

Inset
The sidebar is similar in many ways to the Notes piece, but it is much longer, taking up at least two paragraphs. It provides information that is difficult to include naturally in the text of the section, but which is nevertheless interesting, related to the current material, and may be important to the reader.

When discussing issues network interaction It is often necessary to specify the IP addresses of computers. In most cases, I use addresses allocated for internal networks (192.168.0.0–192.168.255.255, 172.16.0.0–172.31.255.255, and 10.0.0.0–10.255.255.255). I do this so that the reader who unsuccessfully repeats an example from the book does not cause harm real computer connected to the Internet.

Contact Information

If you have any questions while reading the book, you can contact me at

. I also maintain a Web page dedicated to this book, located at

http://www.rodsbooks.com/adv-net/

. Acknowledgments

I would like to thank the editor, Karen Gettman, for her painstaking work in preparing this book for publication. She was assisted in this by project coordinator Emily Frey, who made a number of valuable comments regarding the text of the book. Not a single technical book can be published without the help of consultants who help make sure that the author has not sinned against the truth when presenting the material. Consultants in the preparation of this book were Karel Baloun, Amy Fong, Howard Lee Harkness, Harold Hauck, Eric H. Herrin II, David King, Rob Kolstad, Matthew Miller, Ian Redfern and Alexy Zinin. After their work on the text, not a single error could remain in the book, and if one was discovered, then it was undoubtedly made by me personally. I would also like to thank David King for contributing to numerous and fruitful discussions about Linux networking. Finally, I thank my agents Neil Salkind at Studio B and Michael Slaughter at Addison-Wesley for bringing this book into the hands of readers.

Hello everyone, we continue to study Linux and network technologies, and I present to you another useful book Network tools Linux from 2016. Having studied it, you will be able to greatly improve your skills in this operating system and become a real guru in this field. Unlike Windows platforms, Linux specialists, have higher salaries and less competition in this service market and are always more in demand in any country in the world. From the book you will learn about CentOS and Debian, all the intricacies of their operation and configuration, and get acquainted with command line, thanks to which you can configure absolutely any server, be it virtual machine at your company or a dedicated server with a hosting provider.

This book describes the operation and scope of many servers running on Linux. DHCP server, Samba and NFS servers are covered here,
print servers, NTP server, remote logging tools, and the X Window System. The tools traditionally used to ensure the operation of Internet services have not been forgotten: servers
DNS, SMTP, HTTP and FTP. Much attention is paid to network security issues. This book also covers remote administration tools - tools
Linuxconf, Webmin and SWAT.
This book will undoubtedly be useful to both beginners and experienced system administrators.

Low-level system configuration.
Configuring kernel networking tools.
Configuring TCP/IP network tools.
Alternative protocol stacks.
Starting servers.
Servers in local networks.
Distributing IP addresses using DHCP.
Authentication using Kerberos.
Sharing files and printers using Samba.
Share files using NFS.
Printer sharing.
Time service.
Receiving mail: POP protocols and IMAP.
News server support.
Remote registration on the server.
Organization remote access using X Window and VNC.
Font servers.
Remote administration systems.
Backup.
Internet servers.
Domain administration.
Mail transfer: SMTP protocol.
Web server support.
FTP servers.
Protection and routing tools.
General issues system protection.
Creating a chroot subtree.
Advanced routing tools.
Configuring packet processing tools using iptables.
Organization of virtual private network.

Linux Networking Tools

Dedicated to the victims of September 11, 2001. I hope that good will still triumph over evil.

Introduction

Computer networks have changed our lives. They were almost invisible in the 1970s and even in the 1980s. However, in the early 1990s, something happened. Perhaps it was an appearance World Wide Web and graphical Web browsers, thanks to which the Internet came to many families. The number of network connections may have exceeded some critical limit. Perhaps this limit has been exceeded by the number of network programs. Be that as it may, now everyone knows about networks. And the most important thing is that everyone knows about the existence of the Internet.

The Internet connects millions of computers, many of which run servers - programs that receive requests from clients and process them. Because the protocols on which the Internet is based allow cross-platform communication, data exchange can involve clients and servers running on different computers and in different operating environments. In recent years, Linux has become one of the most popular operating systems. Running on an inexpensive x86 computer, Linux enables efficient operation of servers supporting small to medium-sized hosts. As computer performance increases, it becomes possible to perform Linux environment servers processing large volumes of data. As a result, a system administrator is often required to have the ability to configure a Linux system and the servers running in its environment.

Which servers should you choose? There are hundreds, if not thousands, of server programs. Most books on the Linux system focus on a few popular servers: the HTTP server (usually Apache), remote login servers such as Telnet and SSH, file servers such as NFS and Samba, and several other types of servers. This book covers a wide variety of servers. The variety of issues under consideration does not make it possible to study in detail the operation and configuration features of each of the servers, but still the information provided is enough to ensure the implementation of the corresponding programs. In addition to the most popular servers, this book also discusses tools that usually receive little attention, but which are nevertheless extremely important for the smooth functioning of the network. For example, there are chapters on the DHCP server, the ephemeral server, and the Kerberos system. This book does not cover the basics of networking. It is assumed that the reader already has an understanding of network tools and is going to improve his skills.

The chapters that describe complex servers such as Apache and Samba do not cover them comprehensively. General information about these tools is followed by a discussion of their advanced features, aimed at the administrator with some experience. For beginners, before studying these chapters, it is advisable to read books containing an introductory course in administering these servers.

Who is this book for?

This book contains advanced information about Linux networking tools and is aimed at specialists who have already worked with networks and the Linux system. The first chapters provide information about setting up low-level Linux networking tools. To make sense of the material in these chapters, you need to have a basic understanding of Linux, or at least UNIX, and know the terminology used to describe networking tools. If you are not familiar with the Linux system, it makes sense for you to read introductory materials, for example, the book by Marcel Gagne Linux System Administration: A User's Guide(Addison-Wesley, 2002) or our book with Vicki Stanfield Linux System Administration(Sybex, 2001).

If you want to learn more about servers like Apache and Samba, but don't want to buy a book dedicated entirely to one product, or if you want information about small but very important servers like xntpd and xfs, this book is for you . It also contains numerous practical tips, such as how to start and shut down a server, how to back up information on the network, how to chroot a server, how to build a firewall, etc. This information will allow you to take a fresh look at the process of administering your network and, possibly, improve the performance and reliability of its operation.

In writing this book, I focused on administrators of small and medium-sized networks. Such a network may contain computers running UNIX, Windows, MacOS and other operating systems, and, of course, at least one Linux machine is connected to it. Most chapters describe the general principles of a particular tool and then provide information on how to use it. This book can be used as a reference guide. If you want a book that covers a wide variety of Linux networking tools, this is the book you're looking for.

Linux versions

One of the reasons Linux administration is problematic is that Linux cannot be treated as a single operating system; it is rather a set of systems created on the basis of a single core. Varieties of Linux are called versions or distribution packages. The distribution package includes a kernel, an installation program targeted at a given version of Linux, a set of utilities, special tools, user programs, etc. In addition, any distribution package includes scripts; Some of them are designed for running servers, others for configuring system components. Different distribution packages contain different versions of the kernel and different sets of tools. When installing some distribution packages, special servers are often installed, for example, a mail server, which, depending on the version of Linux, is the sendmail, Exim or Postfix programs. The characteristic features of each version of Linux leave their mark on working with it and especially on its administration.

Many books ignore the differences between different versions of Linux. They focus primarily on one distribution package, with others mentioned only occasionally. When writing this book, I set myself the goal of describing in more or less detail all the popular versions. In particular, it covers the features of Caldera OpenLinux 3.1, Debian GNU/Linux 2.2, Mandrake 8.1, Red Hat 7.2, Slackware 7.0, SuSE 7.3 and TurboLinux 7.0. I did not have the opportunity to examine each system in detail; I tried to draw the reader's attention to the main differences between them. For example, in the book you will find information about what tools are used in each version of Linux to run servers, what programs provide FTP interaction, etc. Some chapters cover various programs that implement a specific type of server. This is done so that you can get an idea of the differences in the default configuration in different distribution packages.

Book structure

The book consists of four parts, each containing from four to thirteen chapters. Servers used to serve local users and servers used to organize interaction over the Internet are described in different parts. However, it should be noted that some servers can be used for different purposes. The contents of each part are briefly described below.

Part I This part is shorter than the others; it contains only four chapters. It describes how to configure the system kernel and provides general information about the configuration of TCP/IP tools, protocol stacks, and startup scripts.

Part II. This part covers servers that will most likely only be accessed by computers on your local network. It discusses the DHCP server, the Kerberos system, Samba and NFS servers, LPD printing, ephemeral servers, POP and IMAP mail servers, news servers, remote login servers, the X Window system and VNC server, font server, remote administration server, and backup tools.

Part III. This part is devoted to the consideration of servers used to work on the Internet. It provides information about DNS servers, mail servers that support the SMTP protocol, Web and FTP servers.

Part IV. This part discusses network security issues. It covers general security issues, tools for creating a chroot subtree, configuring special router features, creating firewalls using iptables, NAT tools, and setting up a VPN.

Conventions adopted in the book

To simplify the understanding of the material presented, the following conventions are adopted in the book.

This book describes the operation and scope of many servers running on Linux. It covers the DHCP server, Samba and NFS servers, print servers, NTP server, remote login tools, and the X Window System. The tools traditionally used to ensure the operation of Internet services have not been forgotten: DNS servers, SMTP, HTTP and FTP. Much attention is paid to network security issues. This book also covers remote administration tools - Linuxconf, Webmin and SWAT tools.

Table of contents .
Part I Low-level system configuration 25
Chapter 1. Configuring kernel networking 26
Chapter 2. Configuring TSRLR network tools 51
Chapter 3. Alternative protocol stacks 81
Chapter 4. Starting Servers 95
Part P. Servers on local networks 125
Chapter 5: Distributing IP Addresses Using DHCP 126
Chapter 6. Kerberos Authentication 145
Chapter 7: Sharing Files and Printers Using Samba 174
Chapter 8: Sharing Files Using NFS 207
Chapter 9: Sharing Printers 223
Chapter 10. Time Service 240
Chapter 11. Receiving Mail: POP and IMAP 254
Chapter 12. News Server Support 278
Chapter 13. Remote Login to Server 300
Chapter 14: Establishing Remote Access Using X Window and VNC 322
Chapter 15. Font Servers 354
Chapter 16. Remote system administration 372
Chapter 17. Backup 390
Part III. Internet Servers 425
Chapter 18. Domain Administration 426
Chapter 19. Mail Transfer: SMTP Protocol 447
Chapter 20. Web Server Support 491
Chapter 21. FTP Servers 534
Part IV. Security and Routing Tools 555
Chapter 22. General system security issues 556
Chapter 23: Creating a chroot subtree 581
Chapter 24: Advanced Routing 592
Chapter 25: Configuring Packet Handling with iptables 607
Chapter 26. Setting up a virtual private network 630
Subject index.

Introduction .
Computer networks have changed our lives. They were almost invisible in the 1970s and even in the 1980s. However, in the early 1990s, something happened. Perhaps it was the advent of the World Wide Web and graphical Web browsers that brought the Internet into many families. The number of network connections may have exceeded some critical limit. Perhaps this limit has been exceeded by the number of network programs. Be that as it may, now everyone knows about networks. And the most important thing is that everyone knows about the existence of the Internet.

The Internet connects millions of computers, many of which run servers - programs that receive requests from clients and process them. Because the protocols on which the Internet is based allow cross-platform communication, data exchange can involve clients and servers running on different computers and in different operating environments. In recent years, Linux has become one of the most popular operating systems. Installed on an inexpensive x86 computer, Linux provides efficient operation of servers supporting small to medium-sized nodes. As computer performance increases, it becomes possible to run servers that process large volumes of data in a Linux environment. As a result, a system administrator is often required to have the ability to configure a Linux system and the servers running in its environment.

In addition to the most popular servers, this book also discusses tools that usually receive little attention, but which are nevertheless extremely important for the smooth functioning of the network. For example, there are chapters on the DHCP server, the ephemeral server, and the Kerberos system. This book does not cover the basics of networking. It is assumed that the reader already has an understanding of network tools and is going to improve his skills.

Free download e-book V convenient format, watch and read:
Download the book Linux Network Tools, Roderick Smith, 2003 - fileskachat.com, fast and free download.

Download pdf
You can buy this book below best price at a discount with delivery throughout Russia.

Network operating system(English Network operating system) is an operating system that provides processing, storage and transmission of data in the information network.

Main tasks network OS are the sharing of network resources (for example, storage spaces) and network administration. System Administrator defines shared resources, sets passwords, defines access rights for each user or group of users. Hence, network operating systems are divided into network operating systems for servers and network operating systems for users.

There are special network operating systems that are given functions conventional systems(for example, Windows NT) and conventional operating systems (Windows XP), which are given network functions. Almost all modern operating systems have built-in network functions.

The network operating system forms the basis of any computer network. Every computer on the network to a large extent standalone, therefore under the network operating system V in a broad sense is understood as a set of operating systems of individual computers interacting for the purpose of exchanging messages and sharing resources according to uniform rules - protocols. These protocols provide the basic functions of the network: addressing objects, functioning of services, ensuring data security, and network management. IN in the narrow sense network OS is an operating system separate computer, providing him with the ability to work on the network.

Depending on how functions are distributed between network computers, network operating systems, and therefore networks are divided into two classes: Peer-to-peer and two-peer, which are more often called networks with dedicated servers.

If a computer provides its resources to other network users, then it plays the role of a server. In this case, a computer accessing the resources of another machine is a client. A computer operating on a network can perform the functions of either a client or a server, or combine both functions.

If performing server functions is the main purpose of a computer, then such a computer is called dedicated server. Depending on which server resource is shared, it is called a file server, fax server, print server, application server, etc. It is not customary to use a dedicated server as a computer to perform routine tasks not related to its main purpose, as this may reduce the performance of its work as a server.

On dedicated servers, it is advisable to install OSes that are specifically optimized to perform certain server functions. Therefore, in such networks, network operating systems are most often used, which include several OS options that differ in the capabilities of the server parts. For example, network OS Novell NetWare has a server version optimized to work as a file server.

In peer-to-peer networks, all computers have equal access rights to each other's resources. Each user can, at his own discretion, declare any resource on his computer as shared, after which other users can use it. In such networks, the same OS is installed on all computers.

A multi-user, multi-tasking operating system that can operate on various hardware platforms. The UNIX OS microkernel has a built-in module that implements the Transmission Control Protocol/Internet Protocol (TCP/IP protocol).

- a network operating system, the kernel of which is developed on the basis of the operating system Unix systems. Linux is distributed with open source source codes and is used to create servers in computer networks and on the Internet.

is a network operating system developed by Novell Corporation that uses a peer-to-peer or client-server architecture.

is a network, multitasking operating system developed by Microsoft Corporation that supports client-server architecture. Windows NT OS comes in two products:

Windows NT Server, which performs server functions;
Windows NT Workstation, which implements client tasks.