Linux Network Administrators Guide

1 Linux Network Administrators GuideTable of Contents1. Purpose and Audience for This Sources of Documentation Available via Documentation Available via Documentation Available Linux Journal and Linux Linux Usenet Linux Mailing Online Linux Linux User Obtaining File System Standard Linux About This The Official Printed Conventions Used in This Submitting The Hall of 1. Introduction to TCP/IP Introduction to TCP/IP Other Types of The Internet IP Over Serial The Transmission Control The User Datagram More on The Socket UUCP Linux Network Administrators GuideiTable of Different Streaks of Where to Get the Maintaining Your System 2. Issues of TCP/IP Networking IP Address IP IP The Routing Metric The Internet Control Message Resolving Host 3. Configuringthe Kernel Kernel Options in Linux and Kernel Networking Options in Linux and A Tour of Linux Network Ethernet Ethernet The PLIP The PPP and SLIP Other Network 4.

2 Configuring the Serial Communications Software for Modem Introduction to Serial Network Administrators GuideiiTable of Accessing Serial The Serial Device Special Serial Using the Configuration The setserial The stty Serial Devices and the login: Configuring the mgetty 5. Configuring TCP/IP Mounting the /proc Installing the Setting the Assigning IP Creating Writing hosts and networks Interface Configuration for The Loopback Ethernet Routing Through a Configuring a The PLIP The SLIP and PPP The Dummy IP All About The netstat Displaying the Routing Displaying Interface Displaying Checking the ARP 6. Name Service and Resolver The Resolver Network Administrators GuideiiiTable of The Resolver environment The Configuring Name Server Lookups Using Resolver How DNS Name Lookups with Types of Name The DNS Reverse Running The The BIND 8 The DNS Database Caching only named Writing the Master Verifying the Name Server Other Useful 7.

3 Serial Line General SLIP Dealing with Private IP Using A Sample A dip The modem The echo The get The print Variable The if and goto send, wait, and mode and Running in Server 8. The Point to Point PPP on Running Network Administrators GuideivTable of Using Options Using chat to Automate IP Configuration Choosing IP Routing Through a PPP Link Control General Security Authentication with PAP Versus The CHAP Secrets The PAP Secrets Debugging Your PPP More Advanced PPP PPP Demand Persistent 9. TCP/IP Methods of What Is a Firewall?.. What Is IP Filtering?.. Setting Up Linux for Kernel Configured with IP The ipfwadm The ipchains The iptables Three Ways We Can Do Original IP Firewall ( Kernels).. Using A na ve An important Listing our A More Complex Summary of ipfwadm Network Administrators GuidevTable of Optional ICMP datagram IP Firewall Chains ( Kernels).

4 Using ipchains Command Rule specification Our Na ve Example Listing Our Rules with Making Good Use of User defined The ipchains support Netfilter and IP Tables ( Kernels).. Backward Compatability with ipfwadmand Using Rule specification Our Na ve Example Revisited, Yet TOS Bit Setting the TOS Bits Using ipfwadm or Setting the TOS Bits Using Testing a Firewall A Sample Firewall 10. IP Configuring the Kernel for IP Configuring IP Accounting by Accounting by Service Accounting of ICMP Accounting by Using IP Accounting Listing Accounting Data with Listing Accounting Data with Listing Accounting Data with Network Administrators GuideviTable of Resetting the Flushing the Passive Collection of Accounting 11. IP Masquerade and Network Address Side Effects and Fringe Configuring the Kernel for IP Configuring IP Setting Timing Parameters for IP Handling Name Server More About Network Address 12.

5 ImportantNetwork The inetd Super The tcpd Access Control The Services and Protocols Remote Procedure Configuring Remote Loginand Disabling the r; Installing and Configuring The ssh The ssh Using 13. The Network Information Getting Acquainted with NIS Versus NIS+.. The Client Side of Running an NIS NIS Server Network Administrators GuideviiTable of Setting Up an NIS Client with GNU Choosing the Right Using the passwd and group Using NIS with Shadow 14. The NetworkFile Preparing Mounting an NFS The NFS The exports Kernel Based NFSv2 Server Kernel Based NFSv3 Server 15. IPX and the NCP Xerox, Novell, and IPX and Caldera More on NDS Configuring the Kernel for IPXand Configuring IPX Network Devices Supporting IPX Interface Configuration The ipx_configure The ipx_interface Configuring an IPX Static IPX Routing Using the ipx_route Internal IPX Networks and Mounting a Remote NetWare A Simple ncpmount The ncpmount Command in Hiding Your NetWare Login A More Complex ncpmount Network Administrators GuideviiiTable of Exploring Some of the Other IPX Server Send Messages to NetWare Browsing and Manipulating Bindery Printing to a NetWare Print Using nprint with the Line Printer Managing Print NetWare Server 16.

6 ManagingTaylor UUCP Transfers and Remote The Inner Workings of uucico Command line UUCP Configuration A Gentle Introduction to Taylor What UUCP Needs to Site Taylor Configuration General Configuration Options Using the config How to Tell UUCP About Other Systems Using the sys System Telephone port and The login Restricting call Identifying Available Devices Through the port How to Dial a Number Using the dial UUCP Over Using a Direct Controlling Access to UUCP Command File Setting Up Your System for Dialing Providing UUCP Protecting Yourself Against Be Paranoid: Call Sequence Anonymous UUCP Low Level Protocol Network Administrators GuideixTable of Tuning the Transmission Selecting Specific uucico Keeps Saying Wrong Time to Call .. uucico Complains That the Site Is Already You Can Connect to the Remote Site, but the Chat Script Your Modem Does Not Your Modem Tries to Dial but Doesn't Get Login Succeeds, but the Handshake Log Files and 17.

7 Electronic What Is a Mail Message?.. How Is Mail Delivered?.. Email RFC Obsolete Mail Mixing Different Mail How Does Mail Routing Work?.. Mail Routing on the Mail Routing in the UUCP Mixing UUCP and RFC Configuring Global elm National Character 18. Introduction to Installing Overview of Configuration The and Two Example Typically Used VERSIONID and Network Administrators GuidexTable of Local macro Defining mail transport Configure mail routing for local Generating the Interpreting and Writing Rewrite R and S Some Useful Macro The Lefthand The Righthand A Simple Rule Pattern Ruleset Interpreting the rule in our Configuring sendmail Some Useful sendmail Trusting Users to Set the From: Managing Mail Using a Smart Managing Unwanted or Unsolicited Mail (Spam).. The Real time Blackhole The access Barring users from receiving Configuring Virtual Email Accepting mail for other Forwarding virtual hosted mail to other Testing Your Running Tips and Managing the Mail Forcing a Remote Host to Process its Mail Analyzing Mail 19.

8 Getting EximUp and Running If Your Mail Doesn't Get Compiling Network Administrators GuidexiTable of Mail Delivery Miscellaneous config Message Routing and Routing Delivering Messages to Local Local Alias Mailing Protecting Against Mail UUCP 20. Usenet What Is Usenet, Anyway?.. How Does Usenet Handle News?..400 Chapter 21. C Delivering The sys The active Article Expiring Miscellaneous Control The cancel newgroup and The checkgroups sendsys, version, and C News in an NFS Network Administrators GuidexiiTable of Maintenance Tools and 22. NNTP and thenntpd The NNTP Connecting to the News Pushing a News Article onto a Changing to NNRP Reader Listing Available Listing Active Posting an Listing New Selecting a Group on Which to Listing Articles in a Retrieving an Article Header Retrieving an Article Body Reading an Article from a Installing the NNTP Restricting NNTP NNTP nntpd Interaction with C 23.

9 Internet Some INN Newsreaders and Installing Configuring INN: the Basic INN Configuration Global The Configuring The active and newsgroups Configuring The newsfeeds The Controlling Newsreader The The Expiring News Network Administrators GuidexiiiTable of The Handling Control The Running Managing INN: The ctlinnd Add a New Change a Remove a Renumber a Allow/Disallow Reject Newsfeed Allow Newsfeed Disable News Restart News Display Status of a Drop a Begin a Cancel an 24. Newsreader tin trn nn A. Example Network :The Virtual Connecting the Virtual Subsidiary B. Useful Cable A PLIP Parallel A Serial NULL Modem C. Linux Network administrator 's Guide , Second Edition Copyright 0. 1. Applicability and 2. Verbatim 3. Copying in Network Administrators GuidexivTable of 4. 5. Combining 6.

10 Collections of 7. Aggregation with Independent 8. 9. 10. Future Revisions of this D. SAGE: The SystemAdministrators Network Administrators Guidexv1. Purpose and Audience for This BookThis book was written to provide a single reference for Network administration in a Linux and experienced users alike should find the information they need to cover nearly all importantadministration activities required to manage a Linux Network configuration. The possible range of topics tocover is nearly limitless, so of course it has been impossible to include everything there is to say on allsubjects. We've tried to cover the most important and common ones. We've found that beginners to Linuxnetworking, even those with no prior exposure to Unix like operating systems, have found this book goodenough to help them successfully get their Linux Network configurations up and running and get them readyto learn are many books and other sources of information from which you can learn any of the topics coveredin this book (with the possible exception of some of the truly Linux specific features, such as the new Linuxfirewall interface, which is not well documented elsewhere) in greater depth.