C sharp Network Programming

C# Network Programming

by Richard Blum ISBN:0782141765

This book helps newcomers get started with a look at the basics of network programming as they

relate to C#, including the language’s network classes, the Winsock interface, and DNS resolution.

Table of Contents

C# Network Programming

Introduction

Part I - Network Programming Basics

Chapter 1 - The C# Language

Chapter 2 - IP Programming Basics

Chapter 3 - C# Network Programming Classes

Chapter 4 - DNS and C#

Part II - Network Layer Programing

Chapter 5 - Connection-Oriented Sockets

Chapter 6 - Connectionless Sockets

Chapter 7 - Using The C# Sockets Helper Classes

Chapter 8 - Asynchronous Sockets

Chapter 9 - Using Threads

Chapter 10 - IP Multicasting

Part III - Application Layer Programming Examples

Chapter 11 - ICMP

Chapter 12 - SNMP

Chapter 13 - SMTP

Chapter 14 - HTTP

Chapter 15 - Active Directory

Chapter 16 - Remoting

Chapter 17 - Security

Index

List of Figures

List of Tables

List of Listings

List of Sidebars

C# Network Programming

by Richard Blum ISBN:0782141765

This book helps newcomers get started with a look at the basics of network programming as they

relate to C#, including the language’s network classes, the Winsock interface, and DNS resolution.

Table of Contents

C# Network Programming

Introduction

Part I - Network Programming Basics

Chapter 1 - The C# Language

Chapter 2 - IP Programming Basics

Chapter 3 - C# Network Programming Classes

Chapter 4 - DNS and C#

Part II - Network Layer Programing

Chapter 5 - Connection-Oriented Sockets

Chapter 6 - Connectionless Sockets

Chapter 7 - Using The C# Sockets Helper Classes

Chapter 8 - Asynchronous Sockets

Chapter 9 - Using Threads

Chapter 10 - IP Multicasting

Part III - Application Layer Programming Examples

Chapter 11 - ICMP

Chapter 12 - SNMP

Chapter 13 - SMTP

Chapter 14 - HTTP

Chapter 15 - Active Directory

Chapter 16 - Remoting

Chapter 17 - Security

Index

List of Figures

List of Tables

List of Listings

List of Sidebars

Back Cover

On its own, C# simplifies network programming. Combine it with the precise instruction found in C# Network

Programming, and you’ll find that building network applications is easier and quicker than ever.

This book helps newcomers get started with a look at the basics of network programming as they relate to C#,

including the language’s network classes, the Winsock interface, and DNS resolution. Spend as much time here as you

need, then dig into the core topics of the network layer. You’ll learn to make sockets connections via TCP, and

“connectionless” connections via UDP. You’ll also discover just how much help C# gives you with some of your

toughest chores, such as asynchronous socket programming, multithreading, and multicasting.

Network-layer techniques are just a means to an end, of course, and so this book keeps going, providing a series of

detailed application-layer programming examples that show you how to work with real protocols and real network

environments to build and implement a variety of applications. Use SNMP to manage network devices, SMTP to

communicate with remote mail servers, and HTTP to Web-enable your applications. And use classes native to C# to

query and modify Active Directory entries.

Rounding it all out is plenty of advanced coverage to push your C# network programming skills to the limit. For

example, you’ll learn two ways to share application methods across the network: using Web services and remoting.

You’ll also master the security features intrinsic to C# and .NET—features that stand to benefit all of your

programming projects.

About the Author

Richard Blum has spent 14 years as a network and system administrator for the US Department of Defense, supporting

a large network of workstations and servers. He holds a BS in Electrical Engineering and an MS in Management

Information Systems, both from Purdue University.

C# Network Programming

Richard Blum

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Acknowledgments

First, all honor, glory, and praise goes to God, who through His Son, all things are possible, and who gives us

the gift of eternal life.

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Denise Santoro Lincoln, the Acquisitions Editor, for offering me the opportunity to write this book. Also, thanks

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in arranging this book for me.

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Barbara and daughters Katie Jane and Jessica for their faith, love, and understanding, especially while I was

writing this book.

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unclear whether he was actually a historical figure. It is said that he was a teacher of Confucius. The

concepts embodied in the Tao Te Ching influenced religious thinking in the Far East, including Zen Buddhism

in Japan. Many in the West, however, have wrongly understood the Tao Te Ching to be primarily a mystical

work; in fact, much of the advice in the book is grounded in a practical moral philosophy governing personal

conduct.

Introduction

Networks (and network programming) have come a long way over the past 20 years. In the early days of

network computing (the ’80s), network programming was left to the advanced programmer, who typically built

applications using the C programming language in (mostly) Unix environments. Now, networks are

everywhere, from large corporations to small home users. With so many computers connected together via

networks, network-aware applications are an accepted necessity. Existing applications must incorporate

network features to stay competitive in the marketplace, and adding network communication to applications is

essential. Network programs are used for everything from children’s games to advanced corporate database

systems.

Network programming has always been a key feature of the Microsoft Windows operating system.

Unfortunately, you’ve had to know advanced C or C++ programming concepts to utilize the network

programming features in Windows programs. Now, though, the .NET Framework languages simplify the task

of adding network features to your applications. The .NET libraries provide many network classes that can

integrate network programming.

As a network administrator, I’ve written many network programs using the C and Java languages for both

Windows and Unix platforms. Today’s network management and security requirements make it essential to

communicate with network devices and track workstations on the network. Trying to quickly write clean

network code can be difficult when you are working within the structure of the C socket APIs (especially in

WinSock), and running Java applications is often a painful experience due to slow processing speeds and

poor Windows support.

The C# language has solved many of my network programming problems by allowing me to quickly

prototype and deploy network applications using C# classes. Combining the C# Forms library to write the

graphical code with the C# Socket library to write the networking code makes creating professional network

applications simple. With C# network classes, what used to take a day to write often only takes an hour or

less.

Who Should Read This Book

Obviously, if you are a C# programmer who is interested in creating network programs, this book is

specifically intended to help you out. I’ve described each network C# class in detail, and you’ll find lots of

examples to help you implement the classes in your own work. If you have never before written a network

program, I’ve included useful explanations of the concepts and ideas behind network programming in

general, including common techniques for passing data between network devices.

You may already be familiar with writing network programs using other languages, such as C, C++, or Java. In

that case, you’ll be interested in seeing how easy it is to do this with the C# language.

If you are new to the C# language, the first chapter describes the basics of creating and compiling C#

programs. You may want to skip other chapters in the first part of the book, which discuss network

programming basics, and dive right into the C#-specific network programming classes.

How This Book Is Organized

This book is organized into four separate sections that cover a particular aspect of network programming.

Part I: Network Programming Basics

The first four chapters are intended for programmers just starting out in network programming and looking for

some background information about how network programming works and the pieces that are required for

network programming.

Chapter 1, “The C# Language,” provides some basic information for the reader new to C#, such as which C#

package to use for development work and how to compile C# programs.

Chapter 2, “IP Programming Basics,” demonstrates how network programming has evolved from the Unix

world to the world of Windows, via the WinSock interface, and how .NET uses the WinSock interface to

access network resources.

Chapter 3, “C# Network Programming Classes,” offers a quick introduction to the entire C# network libraries

and shows the basic formats of the classes.

Chapter 4, “DNS and C#,” rounds out the introductory section by showing network novices how DNS can

resolve host addresses and how to use the C# DNS classes.

Part II: Network Layer Programming

The next group of chapters presents the core of network programming topics in the book. Each of these

chapters discusses a major topic using in creating C# network programs.

Chapter 5, “Connection-Oriented Sockets,” starts the discussion of network programming by introducing

stream programming using TCP. In addition to the standard C# Socket class used for stream programming,

common pitfalls are discussed to help you create stream programs that will work on real networks.

Chapter 6, “Connectionless Sockets,” discusses how to use the Socket class to create UDP applications. In

addition to showing you how to create UDP applications, this chapter also discusses pitfalls related to UDP

programming and shows examples of creating applications that will withstand the problems inherent in real

networks.

Chapter 7, “Using the C# Socket Helper Classes,” discusses the C# TcpClient, TcpListener, and

UdpClient classes. These are special classes in .NET to help programmers create network programs with

minimal effort. This chapter also discusses the basics of sending different data types across the network.

Chapter 8, “Asynchronous Socket Programming,” discusses the technique of using asynchronous

programming (prevalent in Windows programs) within the network programming world.

Chapter 9, “Using Threads,” presents information for using multi-threaded application techniques in network

programs. This technology is often used in server applications that must service multiple clients at the same

time.

Chapter 10, “IP Multicasting,” describes how to use broadcasting and multicasting to send packets to multiple

clients, cutting down on network bandwidth.

Part III: Application Layer Programming Examples

The last part of the book describes specific network applications and how to implement them using the C#

network classes.

Chapter 11, “ICMP,” shows how to use C# raw sockets to implement a protocol-specific application. The

common ping and traceroute programs are shown within the C# network programming context.

Chapter 12, “SNMP,” describes how to write network management applications using C#. SNMP allows you

to communicate with many devices on the network to retrieve network statistics. This chapter shows specific

examples of reading a vendor MIB sheet and creating a C# application to extract the MIB data from the

network device.

Chapter 13, “SMTP,” describes the C# e-mail classes and shows examples of using them to send mail using

SMTP to remote mail servers. Also, an example of using other mail protocols (such as POP3) is shown.

Chapter 14, “HTTP,” presents the C# web classes and how you can use them to create web-enabled C#

applications. Also, .NET web services , and how you can use them to host your application methods on an IIS

server, are discussed.

Chapter 15, “Active Directory,” shows the C# classes for contacting Microsoft Active Directory servers.

Examples are presented that show how to query, change, add, and delete entries in the Active Directory.

Chapter 16, “Remoting,” discusses the .NET concept of remoting, allowing an application to share methods

with clients across the network. Examples are shown that demonstrate how to create both a remoting server

and client.

Chapter 17, “Security,” closes out the book by describing how the .NET Framework handles program

security, and how you can implement security in your network applications using encryption techniques.