Book excerpt: In the last decade, the Internet has grown from a network that connected a few universities and research centers to a network that links many businesses and households all over the country. That expansion occurred for many reasons, but the technological advance that facilitated this growth was an obscure protocol called PPP.PPP isn't talked about as much as TCP and IP, but it plays a crucial role in extending networks into remote locations. The Point-to-Point Protocol enables telephone lines and other point-to-point connections to carry Internet traffic. It's the protocol that establishes and maintains the connection between your home and an Internet service provider. This book provides in-depth coverage of PPP for network administrators and others who are involved in the care and maintenance of PPP connections. It provides a thorough introduction to how PPP works, which will help you diagnose and troubleshoot problems. It discusses in detail how to set up dial-in and dial-out PPP on the most important platforms, including Windows, Linux, and Solaris. Whether you're a sophisticated user responsible for your own connection or a network administrator providing dial-up services for hundreds of remote users, you'll find this book an essential addition to your library. Covers: PPP implementations in Windows 95/98/NT, Solaris, and Linux Authentication (CHAP, PAP, Microsoft variants, and other techniques) Virtual networks and tunnels, including PPTP Modems and serial lines Related technologies, including DNS and ARP Optimizing and customizing a connection Debugging techniques