Linux Networking−HOWTO (Previously the Net−3 Howto) Linux Networking−HOWTO (Previously the Net−3 Howto) Table of Contents Linux Networking−HOWTO (Previously the Net−3 Howto).........................................................................1 Current Author: unmaintained.................................................................................................................1 1. Introduction..........................................................................................................................................1 2. Document History................................................................................................................................1 3. How to use this HOWTO.....................................................................................................................1 4. General Information about Linux Networking....................................................................................1 5. Generic Network Configuration Information......................................................................................1 6. IP− and Ethernet−Related Information................................................................................................2 7. Using common PC hardware...............................................................................................................2 8. Other Network Technologies...............................................................................................................2 9. Cables and Cabling..............................................................................................................................3 10. Glossary of Terms used in this document..........................................................................................3 11. Linux for an ISP ?..............................................................................................................................3 12. Acknowledgements............................................................................................................................3 13. Copyright...........................................................................................................................................3 1. Introduction..........................................................................................................................................3 2. Document History................................................................................................................................3 2.1 Feedback............................................................................................................................................3 3. How to use this HOWTO.....................................................................................................................4 3.1 Conventions used in this document...................................................................................................4 4. General Information about Linux Networking....................................................................................5 4.1 A brief history of Linux Networking Kernel Development...............................................................5 4.2 Linux Networking Resources............................................................................................................6 4.3 Where to get some non−linux−specific network information...........................................................7 5. Generic Network Configuration Information......................................................................................8 5.1 What do I need to start ?....................................................................................................................8 Current Kernel source(Optional).......................................................................................................8 Current Network tools.......................................................................................................................9 Network Application Programs.......................................................................................................10 IP Addresses, an Explanation..........................................................................................................10 5.2 Where should I put the configuration commands ?.........................................................................12 5.3 Creating your network interfaces.....................................................................................................13 5.4 Configuring a network interface......................................................................................................13 5.5 Configuring your Name Resolver....................................................................................................14 What's in a name ?...........................................................................................................................14 What information you will need......................................................................................................15 /etc/resolv.conf................................................................................................................................15 /etc/host.conf...................................................................................................................................16 /etc/hosts..........................................................................................................................................16 Running a name server....................................................................................................................16 5.6 Configuring your loopback interface...............................................................................................17 5.7 Routing.............................................................................................................................................17 So what does the routed program do ?............................................................................................19 5.8 Configuring your network servers and services...............................................................................21 /etc/services.....................................................................................................................................21 An example /etc/services file..........................................................................................................22 /etc/inetd.conf..................................................................................................................................25 An example /etc/inetd.conf..............................................................................................................26 i Linux Networking−HOWTO (Previously the Net−3 Howto) Table of Contents Linux Networking−HOWTO (Previously the Net−3 Howto) 5.9 Other miscellaneous network related configuration files................................................................28 /etc/protocols...................................................................................................................................28 /etc/networks...................................................................................................................................28 5.10 Network Security and access control.............................................................................................29 /etc/ftpusers.....................................................................................................................................29 /etc/securetty....................................................................................................................................29 The tcpd hosts access control mechanism.......................................................................................30 /etc/hosts.allow................................................................................................................................30 /etc/hosts.deny.................................................................................................................................31 /etc/hosts.equiv................................................................................................................................31 Configure your ftp daemon properly...............................................................................................31 Network Firewalling........................................................................................................................32 Other suggestions............................................................................................................................32 6. IP− and Ethernet−Related Information..............................................................................................32 6.1 Ethernet............................................................................................................................................32 6.2 EQL − multiple line traffic equaliser...............................................................................................32 6.3 IP Accounting (for Linux−2.0)........................................................................................................33 6.4 IP Accounting (for Linux−2.2)........................................................................................................35 6.5 IP Aliasing.......................................................................................................................................35