Front cover ABCs of z/OS System Programming Volume 4 SNA, TCP/IP, Hardware interfaces, Enterprise Extender Routing, Parallel Sysplex, Operations TCP/IP applications, Security Paul Rogers ibm.com/redbooks International Technical Support Organization ABCs of z/OS System Programming Volume 4 February 2011 SG24-6984-00 Note: Before using this information and the product it supports, read the information in “Notices” on page vii. First Edition (February 2011) This edition applies to version 1 release 12 modification 0 of IBM z/OS (product number 5694-A01) and to all subsequent releases and modifications until otherwise indicated in new editions. © Copyright International Business Machines Corporation 2011. All rights reserved. Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Notices . vii Trademarks . viii Preface . ix The author who wrote this book . .x Now you can become a published author, too! . .x Comments welcome. .x Stay connected to IBM Redbooks . xi Chapter 1. Introducing z/OS Communications Server. 1 1.1 Communications Server overview. 2 1.2 Features and benefits . 4 1.3 Communications Server overview. 6 1.4 Communications Server protocols . 8 1.5 Communications Server functional overview . 10 1.6 System z physical interfaces. 12 1.7 System z connectivity overview . 14 1.8 VTAM and TCP/IP in Communications Server for z/OS . 16 Chapter 2. VTAM concepts for SNA networks . 19 2.1 SNA implementation and concepts . 20 2.2 VTAM nodes types . 22 2.3 SNA subarea network . 24 2.4 An APPN network . 26 2.5 VTAM subarea nodes . 28 2.6 Domains in a subarea network . 30 2.7 Network node domains in APPN. 32 2.8 Starting VTAM SNA . 34 2.9 Starting VTAM. 36 2.10 VTAM start options . 38 2.11 VTAM start options by function . 40 2.12 VTAM buffers . 43 2.13 VTAM major nodes . 45 2.14 Defining LAN attached devices to VTAM . 47 2.15 VTAM operator commands . 49 Chapter 3. TCP/IP stack . 53 3.1 z/OS Communications Server overview . 54 3.2 Networking on the mainframe . 56 3.3 Hardware network connections. 58 3.4 TCP/IP networking . 60 3.5 TCP/IP stack - TCP/IP address space . 62 3.6 TCP/IP terminology . 63 3.7 IPv4 addressing . 65 3.8 IPv6 addresses . 67 3.9 Internet terms for TCP/IP . 68 3.10 TCP/IP suite of protocols . 70 3.11 Sending application data to the host . 72 3.12 Host configuration tasks . 74 © Copyright IBM Corp. 2011. All rights reserved. iii 3.13 TCP/IP customization . 76 3.14 Configuration files used by TCP/IP . 78 3.15 TCP/IP data sets search order . 80 3.16 DEVICE and LINK statements . 82 3.17 The resolver . 84 3.18 Resolver basic concepts . 86 3.19 Configuring the TCP/IP address space. 87 3.20 z/OS UNIX physical file systems. 89 3.21 TCP/IP family of protocols. 91 3.22 Telnet protocol . 93 3.23 Using sockets . 95 3.24 Using TCP/IP with IMS and CICS . 97 3.25 Using CICS sockets API . 99 3.26 Using IMS with SNA or TCP/IP . 101 Chapter 4. Network connectivity . 103 4.1 System z network connectivity . 105 4.2 TCP/IP and network connectivity . 107 4.3 OSA Express connectivity. 109 4.4 OSA-Express3 or OSA-Express2 Ethernet connectivity . 111 4.5 Ethernet protocol. 112 4.6 Non-QDIO versus QDIO data paths . 114 4.7 Internal Queued Direct Input/Output (iQDIO) . 116 4.8 HiperSockets. 118 4.9 Open Systems Adapter Support Facility (OSA/SF). ..