PPPoE Analysis And Implementation For Linux Operating System

PPPoE (Point-to-Point Protocol over Ethernet) is a specification for connecting multiple computer users on an Ethernet local area network to a remote site through common customer premises equipment. PPPoE can be used to have an office or building-full of users share a common Digital Subscriber Line (DSL), cable modem, or wireless connection to the Internet. PPPoE combines the Point-to-Point Protocol (PPP), commonly used in dialup connections, with the Ethernet protocol, which supports multiple users in a local area network. The PPP protocol information is encapsulated within an Ethernet frame.Now most ISP don't supply PPPoE client for Linux.but do PPPoE clients only for windows . This paper has several main works in order to implement it. Firstly this paper briefly describes PPP protocol .then describes in detail the PPPoE protocol and analysis relationship between PPP protocol and PPPoE aside to related problems for PPPoE such as MTU.DoS.and so on. Secondly this paper analysis principles of relay program and server program and presents some methods how to implement PPPoE relay and PPPoE server's some main modules in Linux. Finally this paper presents three kinds of strategies for implementing it under Linux and describes in detail a user-space implementation of a PPPoE client based to a kind of reason strategy for Linux operating system ,a user-space implementation of PPPoE sniffer in order to catch PPPoE frames and analysis PPPoE tags to find other special tag value and script program for PPPoE client run for ADSL in Linux operating system.