Linux Network Administrators Guide Linux Network Administrators Guide Table of Contents 1. Purpose and Audience for This Book............................................................................................................1 2. Sources of Information...................................................................................................................................2 2.1. Documentation Available via FTP....................................................................................................3 2.2. Documentation Available via WWW...............................................................................................3 2.3. Documentation Available Commercially.........................................................................................3 2.4. Linux Journal and Linux Magazine..................................................................................................4 2.5. Linux Usenet Newsgroups................................................................................................................4 2.6. Linux Mailing Lists..........................................................................................................................5 2.7. Online Linux Support.......................................................................................................................6 2.8. Linux User Groups............................................................................................................................6 2.9. Obtaining Linux................................................................................................................................7 3. File System Standards....................................................................................................................................9 4. Standard Linux Base....................................................................................................................................10 5. About This Book...........................................................................................................................................11 6. The Official Printed Version........................................................................................................................13 7. Overview........................................................................................................................................................15 8. Conventions Used in This Book...................................................................................................................17 9. Submitting Changes......................................................................................................................................18 10. Acknowledgments.......................................................................................................................................19 10.1. The Hall of Fame..........................................................................................................................19 Chapter 1. Introduction to Networking..........................................................................................................21 1.1. History.........................................................................................................................................................22 1.2. TCP/IP Networks.......................................................................................................................................23 1.2.1. Introduction to TCP/IP Networks................................................................................................23 1.2.2. Ethernets......................................................................................................................................24 1.2.3. Other Types of Hardware.............................................................................................................25 1.2.4. The Internet Protocol...................................................................................................................27 1.2.5. IP Over Serial Lines.....................................................................................................................28 1.2.6. The Transmission Control Protocol.............................................................................................28 1.2.7. The User Datagram Protocol.......................................................................................................29 1.2.8. More on Ports...............................................................................................................................29 1.2.9. The Socket Library......................................................................................................................30 1.3. UUCP Networks.........................................................................................................................................31 1.4. Linux Networking......................................................................................................................................32 i Linux Network Administrators Guide Table of Contents 1.4.1. Different Streaks of Development...............................................................................................32 1.4.2. Where to Get the Code.................................................................................................................33 1.5. Maintaining Your System.........................................................................................................................34 1.5.1. System Security...........................................................................................................................34 Chapter 2. Issues of TCP/IP Networking.......................................................................................................36 2.1. Networking Interfaces...............................................................................................................................37 2.2. IP Addresses...............................................................................................................................................38 2.3. Address Resolution....................................................................................................................................40 2.4. IP Routing...................................................................................................................................................41 2.4.1. IP Networks.................................................................................................................................41 2.4.2. Subnetworks.................................................................................................................................41 2.4.3. Gateways......................................................................................................................................42 2.4.4. The Routing Table.......................................................................................................................43 2.4.5. Metric Values...............................................................................................................................45 2.5. The Internet Control Message Protocol...................................................................................................46 2.6. Resolving Host Names...............................................................................................................................47 Chapter 3. Configuringthe NetworkingHardware........................................................................................48 3.1. Kernel Configuration.................................................................................................................................51 3.1.1. Kernel Options in Linux 2.0 and Higher.....................................................................................51 3.1.2. Kernel Networking Options in Linux 2.0.0 and Higher..............................................................53 3.2. A Tour of Linux Network Devices............................................................................................................57 3.3. Ethernet Installation..................................................................................................................................59 3.3.1. Ethernet Autoprobing...................................................................................................................59 3.4. The PLIP Driver........................................................................................................................................62 3.5. The PPP and SLIP Drivers.......................................................................................................................64 3.6. Other Network Types................................................................................................................................65 Chapter 4. Configuring the Serial Hardware.................................................................................................66 4.1. Communications Software for Modem Links.........................................................................................67 4.2. Introduction to Serial Devices...................................................................................................................68 ii Linux Network Administrators Guide Table of Contents 4.3. Accessing Serial Devices............................................................................................................................69