z/VM Version 7 Release 1 TCP/IP User's Guide IBM SC24-6333-02 Note: Before you use this information and the product it supports, read the information in “Notices” on page 457. This edition applies to version 7, release 1, modification 0 of IBM z/VM (product number 5741-A09) and to all subsequent releases and modifications until otherwise indicated in new editions. Last updated: 2020-05-13 © Copyright International Business Machines Corporation 1987, 2020. US Government Users Restricted Rights – Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Figures................................................................................................................. xi Tables................................................................................................................. xv About This Document......................................................................................... xvii Intended Audience................................................................................................................................... xvii Conventions and Terminology..................................................................................................................xvii How the Term “internet” Is Used in This Document......................................................................... xvii How Numbers Are Used in This Document........................................................................................ xvii Syntax, Message, and Response Conventions................................................................................... xvii Where to Find More Information................................................................................................................xx Links to Other Documents and Websites............................................................................................. xx How to Send Your Comments to IBM....................................................................xxi Summary of Changes for z/VM TCP/IP User's Guide........................................... xxiii SC24-6333-02, z/VM Version 7 Release 1 (May 2020)......................................................................... xxiii SC24-6333-01, z/VM Version 7 Release 1 (December 2018)............................................................... xxiii SC24-6333-00, z/VM Version 7 Release 1 (September 2018)..............................................................xxiii SC24-6240-08, z/VM Version 6 Release 4 (August 2017).....................................................................xxiv Firewall Friendly FTP..........................................................................................................................xxiv SC24-6240-07, z/VM Version 6 Release 4 (November 2016)...............................................................xxiv z/VM LDAP Server and Client Utilities z/OS V2.2 Equivalency...........................................................xxv zManager Support Removed...............................................................................................................xxv z/VM System SSL and Utilities z/OS V2.2 Equivalency...................................................................... xxv Domain Name System (DNS) IPv6 Support........................................................................................xxv Chapter 1. Introducing Computer Networks and Protocols......................................1 Computer Networks.....................................................................................................................................1 Internet Environment.................................................................................................................................. 1 Internet Protocol Version 4 and Internet Protocol Version 6.....................................................................2 TCP/IP Protocols and Functions..................................................................................................................4 Link Protocols......................................................................................................................................... 5 Network Protocols..................................................................................................................................5 Transport Protocols................................................................................................................................7 Applications and Protocols.................................................................................................................... 8 Routing....................................................................................................................................................... 10 Internet Addressing...................................................................................................................................10 IPv4 Addressing................................................................................................................................... 10 IPv6 Addressing................................................................................................................................... 13 Chapter 2. Transferring Files Using FTP................................................................23 FTP Command............................................................................................................................................24 The NETRC DATA File................................................................................................................................ 26 The FTP DATA File..................................................................................................................................... 27 Statement Syntax.................................................................................................................................27 FTP DATA File Statements........................................................................................................................ 27 CCONNTIME Statement....................................................................................................................... 28 DATACTTIME Statement......................................................................................................................29 iii DCONNTIME Statement.......................................................................................................................30 EPSV4 Statement................................................................................................................................. 31 FTPKEEPALIVE Statement................................................................................................................... 32 FWFRIENDLY Statement......................................................................................................................33 INACTTIME Statement.........................................................................................................................34 LOADDBCSTABLE Statement...............................................................................................................35 MYOPENTIME Statement.....................................................................................................................36 SECURECONTROL Statement.............................................................................................................. 37 SECUREDATA Statement..................................................................................................................... 38 FTP Subcommands....................................................................................................................................39 Continuing Subcommand Input Strings...............................................................................................42 File Name Formats............................................................................................................................... 43 Fully-Qualified Pathnames...................................................................................................................45 Interpretation of Path Information......................................................................................................46 Storage Space Requirements for Transferred Files............................................................................ 47 File Transfer Methods.......................................................................................................................... 47 File List Formats................................................................................................................................... 49 Transferring Files Using a Web Browser..............................................................................................52 Transferring Files Using Secure FTP....................................................................................................53 ACCT...........................................................................................................................................................53 APPEND......................................................................................................................................................54 ASCII.........................................................................................................................................................