z/OS Communications Server Version 2 Release 3 IP User's Guide and Commands IBM SC27-3662-30 Note: Before using this information and the product it supports, be sure to read the general information under “Notices” on page 405. This edition applies to Version 2 Release 3 of z/OS® (5650-ZOS), and to subsequent releases and modifications until otherwise indicated in new editions. Last updated: 2019-06-21 © Copyright International Business Machines Corporation 2000, 2019. US Government Users Restricted Rights – Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Figures................................................................................................................. xi Tables................................................................................................................ xiii About this document............................................................................................xv Who should read this document................................................................................................................ xv How this document is organized................................................................................................................ xv How to use this document.........................................................................................................................xvi How to contact IBM service.................................................................................................................xvi Conventions and terminology that are used in this information.............................................................. xvi Prerequisite and related information....................................................................................................... xvii Summary of changes for IP User's Guide and Commands................................... xxiii Changes made in z/OS Communications Server Version 2 Release 3................................................... xxiii Changes made in z/OS Communications Server Version 2 Release 2, as updated June 2017............ xxiii Changes made in z/OS Version 2 Release 2............................................................................................xxiii z/OS Version 2 Release 1 summary of changes......................................................................................xxiv Chapter 1. Getting started with TCP⁄IP................................................................... 1 Understanding TCP⁄IP.................................................................................................................................. 1 Understanding TCP⁄IP: The physical network........................................................................................1 Understanding TCP⁄IP: Protocols........................................................................................................... 1 Understanding TCP⁄IP: Network devices............................................................................................... 2 Understanding TCP⁄IP: Addresses......................................................................................................... 2 How TCP⁄IP uses networks.......................................................................................................................... 2 How TCP⁄IP uses networks: Local and remote nodes........................................................................... 2 How TCP⁄IP uses networks: Client and server.......................................................................................2 How TCP⁄IP uses networks: TCP⁄IP addresses...................................................................................... 2 How TCP⁄IP uses networks: Network names.........................................................................................3 How TCP⁄IP uses networks: Ports and port numbers............................................................................3 Understanding what you can do with TCP⁄IP.............................................................................................. 3 Logging on to other hosts....................................................................................................................... 3 Transferring data sets between hosts....................................................................................................4 Sending mail........................................................................................................................................... 4 Remote command execution................................................................................................................. 4 Printing to or from other hosts............................................................................................................... 4 What you need to get started with TCP⁄IP...................................................................................................5 Testing commands with loopback............................................................................................................... 5 Obtaining command help.............................................................................................................................6 Chapter 2. Logging on to a host using TELNET......................................................... 7 Using the TSO TELNET command................................................................................................................7 TELNET command ................................................................................................................................. 8 Using the TELNET subcommands............................................................................................................. 10 AO—Terminate output display .............................................................................................................10 AYT—Query the connection .................................................................................................................11 BRK—Send a Break or Attention keystroke to a host ..........................................................................11 HELP or ?—Display help information ...................................................................................................11 IP—Interrupt the process ....................................................................................................................12 iii PA1—Send the PA1 keystroke to a host ..............................................................................................13 QUIT—End the TELNET session .......................................................................................................... 13 SYNCH—Clear the data path ............................................................................................................... 13 ¢ and `—Send ASCII control characters to a host in line mode .........................................................14 Using the TELNET function keys................................................................................................................14 Transparent mode function keys......................................................................................................... 15 Line mode function keys...................................................................................................................... 15 Suppressing carriage return and line feed................................................................................................ 15 Using TELNET 3270 DBCS transform mode..............................................................................................16 Terminal and conversion type..............................................................................................................17 Chapter 3. File Transfer Protocol (FTP)................................................................. 19 Using FTP................................................................................................................................................... 19 FTP command — Entering the FTP environment ................................................................................ 19 Logging in to FTP.................................................................................................................................. 24 Interpreting FTP client output............................................................................................................. 25 Allocating FTP input and output data sets.......................................................................................... 27 UTF-8 enabled control connection...................................................................................................... 27 NETRC data set.....................................................................................................................................28 Environment variables accessed by FTP............................................................................................. 29 FTP Help subcommands............................................................................................................................30 Establishing and exiting a connection.......................................................................................................30 Example of establishing and exiting a connection.............................................................................. 31 Initial working directory