Book Image

Squid Proxy Server 3.1: Beginner's Guide

Book Image

Squid Proxy Server 3.1: Beginner's Guide

Overview of this book

Squid Proxy Server enables you to cache your web content and return it quickly on subsequent requests. System administrators often struggle with delays and too much bandwidth being used, but Squid solves these problems by handling requests locally. By deploying Squid in accelerator mode, requests are handled faster than on normal web servers making your site perform quicker than everyone else's! Squid Proxy Server 3.1 Beginner's Guide will help you to install and configure Squid so that it is optimized to enhance the performance of your network. The Squid Proxy Server reduces the amount of effort that you will have to put in, saving your time to get the most out of your network. Whether you only run one site, or are in charge of a whole network, Squid is an invaluable tool that improves performance immeasurably. Caching and performance optimization usually requires a lot of work on the developer's part, but Squid does all that for you. This book will show you how to get the most out of Squid by customizing it for your network. You will learn about the different configuration options available and the transparent and accelerated modes that enable you to focus on particular areas of your network. Applying proxy servers to large networks can be a lot of work as you have to decide where to place restrictions and who should have access, but the straightforward examples in this book will guide you through step by step so that you will have a proxy server that covers all areas of your network by the time you finish the book.
Table of Contents (20 chapters)
Squid Proxy Server 3.1 Beginner's Guide
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Access control lists


Access Control Lists are the base elements in the Squid configuration file, which help in identifying web transactions, by various attributes of that transaction. We have already learned about the syntax for constructing ACLs in Chapter 2. So, let's write an ACL element that can identify all the requests from a group of clients in the IP range 192.0.2.1 to 192.0.2.127.

acl clients src 192.0.2.0/25

That was quite easy, as 192.0.2.0/25 denotes that the first 25 bits of the available 32 bits in the IP address are fixed and only the last seven bits can vary, which will result in the range 0-127. In the configuration above, 192.0.2.0/25 denotes a subnet with 127 possible IP addresses. For more information on subnets, please check http://en.wikipedia.org/wiki/Subnetwork#IPv4_subnetting.

In the previous ACL element, we used the src ACL type to identify the IP address of the source of the request. There are various other ACL types available, which can be used to identify requests...