Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 1: Base Functions, Connectivity, and Routing

© Copyright IBM Corp. 2006. All rights reserved. ix

Preface

For more than 40 years, IBM® mainframes have supported an extraordinary portion of the

world's computing work—providing centralized corporate databases and mission-critical

enterprise-wide applications. The IBM System z9™, the latest generation of the IBM

distinguished family of mainframe systems, has come a long way from its IBM System/360™

heritage. Likewise, its z/OS® operating system is far superior to its predecessors—providing,

among many other capabilities, world-class, state-of-the-art, support for the TCP/IP Internet

protocol suite.

TCP/IP is a large and evolving collection of communication protocols managed by the

Internet Engineering Task Force (IETF), an open, volunteer organization. Because of its

openness, the TCP/IP protocol suite has become the foundation for the set of technologies

that form the basis of the Internet. The convergence of IBM mainframe capabilities with

Internet technology, connectivity, and standards—particularly TCP/IP—is dramatically

changing the face of information technology and driving requirements for ever more secure,

scalable, and highly available mainframe TCP/IP implementations.

This new and improved Communications Server (CS) for z/OS TCP/IP Implementation series

provides easy to understand step-by-step how-to guidance on enabling the most commonly

used and important functions of CS for z/OS TCP/IP.

In Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 1 - Base

Functions, Connectivity, and Routing, SG24-7169, we begin by providing an introduction to

CS for z/OS TCP/IP. We then discuss the System Resolver, showing the implementation of

global and local settings for single and multi-stack environments. We then present

implementation scenarios for TCP/IP base functions, connectivity, and routing. Finally, we

discuss the IP version 6 support available with the z/OS V1R7.0 Communications Server.

For more specific information about CS for z/OS standard applications, high availability, and

security, please reference the other volumes in the series. These are:

򐂰 Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 2 - Standard

Applications, SG24-7170

򐂰 Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 3 - High

Availability, Scalability, and Performance, SG24-7171

򐂰 Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 4 - Security,

SG24-7172

Our implementation environment

We wrote the four books in the Communications Server for z/OS V1R7 Implementation

guides at the same time. Given the complexity of our test environment, we needed to be

somewhat creative in organizing the environment so that each team could work with minimal

coordination with (and interference from) the other teams.

The environment used for all four books

To enable concurrent work on each of the four books, we set up and shared the test

environment illustrated in Figure 1 on page x.

x Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 1 - Base Functions, Connectivity, and Routing

Figure 1 Our implementation environment

Our books were written (and implementation scenarios executed) using three logical

partitions (LPARs) on an IBM System z9 109 (referred to as A22, A23, and A24). Because we

were working on four books at the same time, we implemented

four TCP/IP stacks on each

LPAR (admittedly, a configuration not recommended for a production environment, but

convenient for our purposes). Each LPAR shared:

򐂰 HiperSockets™ connectivity

򐂰 Coupling Facility connectivity (CF38 and CF39) for parallel sysplex scenarios

򐂰 Four OSA-Express2 1000BASE-T Ethernet ports cross-connected to a pair of Cisco 6509

switches

Finally, we shared ten workstations, representing corporate network access to the z/OS

networking environment, for scenario verification (using applications such as TN3270 and

FTP).

Our IP addressing convention is as follows:

򐂰 The first octet is the network (always 10 for our environment).

򐂰 The second Octet is the VLAN (10,20,30,40) assigned to the stack. (Essentially, except

when required by a specific implementation scenario, each team’s stacks shared a

common VLAN.)

򐂰 The third octet refers to the device:

– The addresses with the third octet of 2 or 3 are defined to the OSA devices.

– The addresses with the third octet of 4, 5, or 6 are defined to the HiperSocket devices.

򐂰 The last octet is made up as follows:

– The first two digits are the LPAR number.

– The last digit is the CHPID number.

Important: Our use of multiple TCP/IP stacks on each LPAR and our TCP/IP addressing

were set up for our convenience and are not recommended approaches for your

environment.