ABSTRACT
This chapter explores the Squid Proxy Server as a forward proxy server. It examines how to install and run Squid. The chapter focuses on the access control list (ACL) of Squid, which allows one to use Squid as a firewall. Squid's caches can be used to cache resources retrieved using Hypertext Transfer Protocol (HTTP), Hypertext Transfer Protocol Secure (HTTPS), File Transfer Protocol (FTP), and Gopher. Squid's primary features are its caching capabilities and its ACLs. Although Squid has many features and functions, it is foremost a server-to-cache web resource. The chapter then examines some of the specific directives to control the cache. There are currently four different file system types available: ufs, aufs, diskd, and rock. These four types represent the default Unix/Linux file system, an asynchronous version of the Unix/Linux file system, a nonthreaded daemon-driven version of a file system, and database-style storage, respectively.
