Bull AIX 4.3 System Management Guide Communications and Networks AIX ORDER REFERENCE 86 A2 31JX 02 Bull AIX 4.3 System Management Guide Communications and Networks AIX Software October 1999 BULL ELECTRONICS ANGERS CEDOC 34 Rue du Nid de Pie – BP 428 49004 ANGERS CEDEX 01 FRANCE ORDER REFERENCE 86 A2 31JX 02 The following copyright notice protects this book under the Copyright laws of the United States of America and other countries which prohibit such actions as, but not limited to, copying, distributing, modifying, and making derivative works. Copyright Bull S.A. 1992, 1999 Printed in France Suggestions and criticisms concerning the form, content, and presentation of this book are invited. A form is provided at the end of this book for this purpose. To order additional copies of this book or other Bull Technical Publications, you are invited to use the Ordering Form also provided at the end of this book. Trademarks and Acknowledgements We acknowledge the right of proprietors of trademarks mentioned in this book. AIXR is a registered trademark of International Business Machines Corporation, and is being used under licence. UNIX is a registered trademark in the United States of America and other countries licensed exclusively through the Open Group. Year 2000 The product documented in this manual is Year 2000 Ready. The information in this document is subject to change without notice. Groupe Bull will not be liable for errors contained herein, or for incidental or consequential damages in connection with the use of this material. About This Book This book is for AIX system administrators who maintain the system’s network connections. Familiarity with the Base Operating System and the material covered in AIX 4.3 System Management Guide: Operating System and Devices and AIX 4.3 System User’s Guide: Communications and Networks is necessary. Who Should Use This Book This book is intended for system administrators who perform system management tasks that involve communication within a network. How to Use This Book Each chapter provides overview, installation and configuration, maintenance, troubleshooting, and reference information in roughly that order. Procedural information is located near the relevant conceptual information for easier access. Highlighting The following highlighting conventions are used in this book: Bold Identifies commands, keywords, files, directories, and other items whose names are predefined by the system. Italics Identifies parameters whose actual names or values are to be supplied by the user. Monospace Identifies examples of specific data values, examples of text similar to what you might see displayed, examples of portions of program code similar to what you might write as a programmer, messages from the system, or information you should actually type. ISO 9000 ISO 9000 registered quality systems were used in the development and manufacturing of this product. AIX Support for the X/Open UNIX95 Specification The AIX operating system is designed to support the X/Open UNIX95 Specification for portability of UNIX–based operating systems. Many new interfaces, and some current ones, have been added or enhanced to meet this specification. AIX 4.3 is even more open and portable for applications. At the same time, compatibility with previous AIX releases is preserved. This is accomplished by the creation of a new environment variable that can be used to set the system environment on a per–system, per–user, or per–process basis. To determine the proper way to develop a UNIX95–portable application, you may need to refer to the X/Open UNIX95 Specification. Preface iii Related Publications The following book contains information about or related to communications: AIX and Related Products Documentation Overview, order number 86 A2 71WE. AIX 4.3 System Management Guide: Operating System and Devices, order number 86 A2 99HX. AIX 4.3 System User’s Guide: Communications and Networks, order number 86 A2 98HX. AIX General Programming Concepts: Writing and Debugging Programs, order number 86 A2 34JX. AIX Commands Reference, order number 86 A2 38JX to 86 A2 43JX. AIX 4.3 Installation Guide, order number 86 A2 43GX. The TTY Subsystem Overview in AIX General Programming Concepts: Writing and Debugging Programs provides general information on line disciplines and the tty code. See also the following industry publications: Token–Ring Network Architecture Reference, order number SC30–3374. Albitz, Paul and Liu, Cricket, [1992], DNS and BIND in a Nutshell, O’Reilly & Associates, Inc., Sebastopol, CA, ISBN 0–56592–010–4. Comer, Douglas E., [1991], Internetworking with TCP/IP, Volume I: Principles, Protocols, and Architectures, Prentice Hall, Englewood Cliffs, NJ, ISBN 0–13–468505–9. Comer, Douglas E. and Stevens, David L., [1991], Internetworking with TCP/IP, Volume II: Design, Implementation, and Internals, Prentice Hall, Englewood Cliffs, NJ, ISBN 0–13–472242–6. Costales, Bryan, Eric Allman, and Neil Rickert, sendmail, O’Reilly & Associates, Inc., Sebastopol, CA, 1993. Hunt, Craig, [1992], TCP/IP Network Administration, O’Reilly & Associates, Inc., Sebastopol, CA, ISBN 0–93–717582–X. Stern, Hal, [1991], Managing NFS and NIS, O’Reilly & Associates, Inc., Sebastopol, CA, ISBN 0–93–717575–7. Stevens, Richard W., [1990], UNIX Network Programming, Prentice Hall, Englewood Cliffs, NJ, ISBN 0–13–949876–1. Tanenbaum, Andrew S., Computer Networks, Prentice Hall, Englewood Cliffs, NJ, ISBN 0–13–165183–8. Vanel, Laurent, Steve Gardner, Praben Prima, Simon Robertson, and Oreste Villari, AIX and Windows NT: Solutions for Interoperability, International Business Machines, Inc. http://www.redbooks.ibm.com Ordering Publications You can order this book separately from Bull Electronics Angers S.A. CEDOC. See address in the Ordering Form at the end of this book. To order additional copies of this book, use order number 86 A2 31JX. Use AIX and Related Products Documentation Overview for information on related publications and how to obtain them. iv System Management Guide: Communications and Networks Contents About This Book . iii Chapter 1. Communications and Networks Overview . 1-1 Communications Functions Introduction . 1-2 Network Introduction . 1-3 Physical Networks Introduction . 1-5 System Communications Support . 1-6 Protocols . 1-6 Addresses . 1-6 Domains . 1-6 Gateways and Bridges . 1-7 Routing . 1-7 Local and Remote Nodes . 1-7 Server and Client . 1-7 Communicating with Other Operating Systems . 1-8 Chapter 2. Mail . 2-1 Mail Management Tasks . 2-2 Configuring the /etc/rc.tcpip File to Start the sendmail Daemon . 2-2 Managing Mail Aliases . 2-3 /etc/aliases File . 2-3 Creating Local System Aliases for Mail . 2-4 Building the Alias Database . 2-4 Managing the Mail Queue Files and Directories . 2-6 Printing the Mail Queue . 2-6 Mail Queue Files . 2-6 Specifying Time Values in sendmail . 2-8 Forcing the Mail Queue . 2-8 Setting the Queue Processing Interval . 2-9 Moving the Mail Queue . 2-9 Starting the sendmail Daemon . 2-10 Stopping the sendmail Daemon . 2-10 Managing Mail Logging . 2-11 Managing the Log . 2-12 Logging Traffic . 2-12 Logging Mailer Statistics . 2-12 Displaying Mailer Information . 2-13 Debugging sendmail . 2-14 Internet Message Access Protocol (IMAP) and Post Office Protocol (POP) . 2-15 Configuring IMAP and POP Servers . 2-15 syslog Facility . 2-17 Mail Reference . 2-18 List of Mail Commands . 2-18 List of Mail Files and Directories . 2-18 List of Internet Message Access Protocol and Post Office Protocol Commands 2-19 Chapter 3. Transmission Control Protocol/Internet Protocol . 3-1 Planning Your TCP/IP Network . 3-2 Installation and Configuration for TCP/IP . 3-3 Configuring TCP/IP . 3-3 Preface v TCP/IP System Manager Commands . 3-4 Configuring a TCP/IP Network Checklist . 3-4 TCP/IP Protocols . 3-6 Internet Protocol (IP) Version 6 Overview . 3-9 IPv6 in AIX: Supplementary Information . 3-16 Packet Tracing . 3-20 Network Interface Packet Headers . 3-20 Internet Network–Level Protocols . 3-23 Internet Transport–Level Protocols . ..