Troubleshooting Guide

Chapter 4. Troubleshooting Host Communications

You can establish connections to and from host database systems, including DB2 Universal Database for OS/390, DB2 for MVS/ESA, DB2 for VM, DB2 for VSE, or DB2 Universal Database for AS/400. Two types of host connections exist:

• Host clients can connect to a DB2 Universal Database server to query and update data. For information on setting up this type of connection, see your server's Quick Beginnings guide.
• DB2 Connect connections allow Windows, OS/2, and UNIX-based clients to interact with host databases. These connections are enabled with the following products:
  • DB2 Connect Personal Edition, for single users
  • DB2 Connect Enterprise Edition, for multiple users through a gateway

  DB2 Connect gateway capability is also provided by DB2 Universal Database Enterprise Edition and DB2 Universal Database Enterprise - Extended Edition.

  For information on DB2 Connect, see the following documents:

  • DB2 Connect Enterprise Edition for OS/2 and Windows Quick Beginnings
  • DB2 Personal Edition Quick Beginnings for your platform
  • DB2 Connect User's Guide
  • Connectivity Supplement

DB2 database communication requires Distributed Relational Database Architecture (DRDA). For information, you can order the following publications separately:

• DRDA Connectivity Guide
• DRDA Problem Determination Guide for information on error analysis in a DRDA environment

DRDA requires communication layers between systems. The Quick Beginnings guides provide detailed steps to establish this communication, which can be enabled in several ways:

• Systems Network Architecture (SNA) enables communication between most systems. Its layered structure allows transparent access to the data on those machines set up to use the SNA network. SNA network communication for LU 6.2 is enabled through the APPC communication protocol. For more information, see APPC Problems.
• TCP/IP is supported by DB2 Universal Database and by Version 5.1 of DB2 for OS/390. For more information, see TCP/IP Problems.

This chapter provides the following troubleshooting sections:

• Troubleshooting Host Connections
• Troubleshooting Tips for Host Connections to DB2 Universal Database

Important: These sections represent a small sampling of the information available from DB2 Customer Support. For a complete and up-to-date source of DB2 information, use the DB2 Product and Service Technical Library on the Web, at http://www-4.ibm.com/software/data/db2/library/ (Note that this information is in English only.)