Introduction to the New Mainframe: Networking

1 To the New Mainframe: NetworkingChristopher HastingsMatt NuttallMicky ReichenbergConcepts of mainframe -based data communicationsMethods for implementing TCP/IP and SNA on z/OSBasic skills in network operations, security, and problem determinationFront coverIntroduction to the New mainframe : NetworkingAugust 2006 International Technical Support OrganizationSG24-6772-00 Copyright International Business Machines Corporation 2006. All rights to Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADPS chedule Contract with IBM Edition (August 2006)This edition applies to Version 1, Release 7, Modification 0 of z/OS (5694-A01). Note: Before using this information and the product it supports, read the information in Notices on page 329.

2 Iiiiv Introduction to the New mainframe : Networking Copyright IBM Corp. 2006. All rights .. xiiiHow this text is organized .. xivHow each chapter is organized .. xvThe team that wrote this redbook .. xviComments welcome .. xviiPart 1. Introduction to Networking on the mainframe .. 1 Chapter 1. Mainframes and networks .. Mainframes, networks, and you .. Networks and online systems .. Why are networks important? .. Examples of mainframe -based networks .. ATM cash withdrawal .. Credit purchase at a retail store .. Technology choices abound in network technology .. Who supports the network?.. What are the basic elements of a network? .. Overview of mainframe network capabilities .. z/OS Communications Server.

3 SNA and TCP/IP on z/OS .. Security in a network .. Data protection .. Availability .. Summary .. 19 Chapter 2. Network layers and protocols review .. Coming to terms .. Layers .. Physical media, layer 1 .. Network interface card (NIC).. Data link layer, layer 2 .. Ethernet.. Media access control (MAC) addressing .. Network layer, layer 3 .. Address Resolution Protocol (ARP) .. Network types .. Local area network (LAN) .. Wide area network (WAN) .. 30vi Introduction to the New mainframe : Virtual LAN .. Network routing .. Building routing tables .. Internet Control Message Protocol (ICMP) .. Other layer 3 protocols .. Transport layer, layer 4 .. Transmission Control Protocol (TCP).

4 User Datagram Protocol (UDP).. Sockets .. Applications .. Security .. Firewalls and gateways .. Security protocols .. Protection .. Systems Network Architecture (SNA) .. Summary .. 43 Chapter 3. Hardware connectivity on the mainframe .. Connecting the mainframe .. Channel subsystem (CSS) .. Control units .. Logical channel subsystem (LCSS) .. The mainframe channel subsystem and network links .. Hardware channels .. Channel command word (CCW) .. CCW-based operations .. Parallel channel.. Enterprise System Connectivity (ESCON) channel .. Fiber connection (FICON) .. Channel-attached network devices .. Coupling channels .. Open Systems Adapter (OSA) .. Queued Direct I/O (QDIO).

5 Non-QDIO mode .. OSC mode .. Open Systems Adapter for NCP (OSN) .. HiperSockets .. Making the connections.. Summary .. 67 Chapter 4. Sample configuration .. Requirements for a mainframe network .. The ZOS Company data center .. 70 Contents Key mainframe network availability aspects .. Summary .. 77 Part 2. TCP/IP implementation on the mainframe .. 79 Chapter 5. TCP/IP on z/OS.. The heart of the matter .. Control issues and the stack .. IPv4 versus IPv6 .. The TCP/IP profile .. Profile statements .. The FTP server .. Character sets - FTP server .. The telnet daemon .. Character sets - telnet daemon .. A good resolver is hard to find.. Searching for resolver configuration information.

6 The multi-stack environment .. TCP/IP clients .. Character sets .. Summary .. 102 Chapter 6. TCP/IP in a sysplex.. Computer cluster .. The z/OS sysplex .. Cross-system Coupling Facility (XCF) .. Workload Manager (WLM) .. Dynamic virtual addressing .. Unique application-instance DVIPA .. Multiple application-instance DVIPA .. Why DVIPA? .. Dynamic cross-system coupling .. VTAM and XCF .. Establishing the links.. More than just XCF .. Sysplex distributor .. What is a tightly-coupled host to do? .. Sysplex distributor in action .. Moving distribution to the network.. Problem detection and recovery in the cluster .. Routing in a sysplex .. Open Shortest Path First (OSPF).

7 Network interface card .. Summary .. 128viii Introduction to the New mainframe : NetworkingPart 3. SNA and SNA/IP implementation on the mainframe .. 131 Chapter 7. Systems Network Architecture - basics and What is Systems Network Architecture (SNA)? .. History .. What you need to know about SNA today .. The evolution of SNA .. Subarea Networking .. SNA nodes .. System services control point (SSCP) .. Subareas and domains .. Connecting subarea nodes .. Architectural components of the SNA network .. VTAM subarea definitions .. Start options .. Configuration lists .. Defining resources to VTAM .. Sample network .. Summary .. 162 Chapter 8. SNA Advanced Peer-to-Peer Networking (APPN).

8 Introduction .. Advanced Program-to Program Communications (APPC) .. Advanced Peer-to-Peer Networking (APPN) .. APPC versus APPN .. APPN node types .. Low-entry Networking (LEN) nodes .. End nodes (EN).. Network nodes (NN) .. Specialized network node types .. Specialized VTAM Nodes .. Control point (CP-CP) sessions .. End node CP-CP sessions .. Network node CP-CP sessions .. NETID considerations .. APPN databases .. Topology database (TOPO DB) .. Directory services database (DS DB) .. APPN network topology .. Topology data update (TDU) flows .. Locating resources .. Route calculation.. Transmission group (TG) characteristics .. 194 Contents Class of service (CoS).

9 Choosing session paths .. High performance routing (HPR) .. Rapid transport protocol (RTP) .. Automatic network routing (ANR) .. HPR headers.. Path switching .. Connection networks .. Dependent LU requester/server (DLUR/DLUS) .. Defining a VTAM APPN network .. Summary .. 209 Chapter 9. SNA/IP implementation.. Background .. Why preserve SNA applications? .. SNA applications and integration methods .. DLSw and Logical Link Control 2 (LLC2) .. Establishing an LLC2 connection over a LAN .. Data link switching (DLSw) .. DLSw over the WAN .. Connecting SDLC devices using DLSw .. DLSw configuration .. Enterprise Extender.. What is it? .. Why does Enterprise Extender use UDP packets?

10 Class of service (CoS) .. EE implementation in non-z/OS remote sites .. Internet connectivity exploitation .. Comparing Enterprise Extender and DLSw .. Implementing Enterprise Extender .. Configuration examples.. Enterprise Extender configuration .. Extended border node configuration .. Cisco SNASw definitions.. Summary .. 239 Chapter 10. TN3270 Enhanced.. Introduction .. 3270 data stream .. TN3270 Enhanced (TN3270E) .. Telnet protocol and SNA meet .. TN3270E description.. Additional functions supported in z/OS .. 249x Introduction to the New mainframe : Positioning a TN3270E server.. Implementing the TN3270E server .. TELNETPARMS statement block .. BEGINVTAM statement block.