This document provides instructions for building an intranet using Linux Ubuntu. It discusses configuring Ubuntu for use as an intranet server, including setting up networking, DHCP, DNS, Apache web server, PHP, SSL certificates, FTP, Squid proxy server, Postfix email server, and user accounts. It also shows commands for testing the intranet configuration. The goal is to have a fully functioning intranet with network services like website, email, file sharing, and caching proxy.