Troubleshooting Guide

Troubleshooting Tips for DB2 Connect

This section describes how to deal with some frequent problems faced by users when trying to connect to host databases using DB2 Connect. It addresses the following topics:

• Problems Encountered after Initial Connection
• Changing the Number of Connections
• Authentication Problems
• Windows Clients Do Not Connect

Problems Encountered after Initial Connection

If you installed a client and could make an initial connection, but then experience a problem with it later, use the following checklist as a starting point to narrow down the scope of the problem.

Can you establish a host session?

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See Troubleshooting Host Connections.

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If you suspect a problem with your communication protocol, see Chapter 3, Troubleshooting on the Client.

Are there any special or unusual operating circumstances?

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Is this a new application?

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Are new procedures being used?

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Have any of the software products or applications been changed since the application or scenario last ran successfully?

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For application programs, what application programming interfaces (APIs) are called?

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Have other applications that use the software or communication APIs been run on the user's system?

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Are there recent changes that might be affecting the system? For example, has maintenance been applied?

Is there relevant diagnostic information?

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Were any SQL messages or SQL states returned? To look up an SQL state or SQL code, see the Message Reference.

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Check the db2diag.log file on the server, particularly for SQLCA information. For more details, see First Failure Data Capture.

Changing the Number of Connections

To change the number of connections that a DB2 Connect Enterprise Edition gateway supports:

• Change the session limit within the mode definition.
• Define the session limit in the APPLID definition for the DB2 subsystem in VTAM (for DB2 for MVS/ESA and DB2 for VM host sessions).
• Change the MAXDBAT parameter in the DSNZPARM dataset for DB2 for MVS/ESA.
• Check the maximum number of database manager agents specified with the DB2 database manager configuration parameter maxagents.

VTAM and Communications Server will negotiate how many DRDA connections are allowed (with a minimum of two). DB2 for MVS/ESA allows only the number of connections defined in the DSNZPARM dataset.

Authentication Problems

Your operating system and communications products may affect the authentication of DB2 Connect sessions. For information, see the Administration Guide: Implementation.

Note that:

• User names and passwords may be case-sensitive. In particular:
  • For DB2 for MVS/ESA, user names and passwords may be case-sensitive depending on which PTFs were applied.
  • Passwords on UNIX-based environments are always case-sensitive.
  • If OS/2 uses User Profile Manager (UPM), user names and passwords are converted to uppercase. This may be an issue if you are using a DB2 Connect Enterprise Edition gateway on a UNIX machine.
• For NetBIOS connections, when you set up a connection to a host from any client via a DB2 Connect Enterprise Edition gateway, the user name and password are passed through to the target server for verification. For example, authorization is always forced to DB2 for MVS/ESA.

  Because of this behavior, DCS authentication does not apply for the NetBIOS protocol: only SERVER authentication should be used.

SQL1403N When Issuing a Connect to DB2 for MVS/ESA

Symptom

The SQL1403N message occurs when a DB2 Connect client tries to connect to DB2 for MVS/ESA using DCS authentication.

Possible Cause

System tables are not set up correctly in DB2 for MVS/ESA to process the incoming request.

Action

Ensure that entries are correct in the SYSIBM.SYSLUNAMES and SYSIBM.SYSUSERNAMES tables.

For more information, see the MVS Server worksheet in the DB2 Connect Enterprise Edition for OS/2 and Windows Quick Beginnings.

SQL1402N and SQL30082N When Connecting to DB2 for MVS/ESA

Symptom

The SQL1402N and SQL30082N messages are received when a client tries to connect to DB2 for MVS/ESA using DB2 Connect.

Possible Cause

You may have established incorrect security authentication between the client, DB2 Connect, and the server.

Action

Specify DCS authentication on your DB2 Connect Enterprise Edition gateway.

If you use SERVER authentication with an OS/2 server, ensure that the user name and password are also defined on the OS/2 server.

Note that the Control Center always assumes SERVER authentication, so you must use the command line processor to set other authentication types.

Windows Clients Do Not Connect

Symptom

The SQL30073N message is received with reason code X'119C' when a Windows client tries to connect to a host database.

Possible Cause

Your host does not recognize the code pages used by your client for one of the following reasons:

• The host cannot support them.
• The host was not set up to support them.
• The host requires a PTF to be applied.

Action

If possible, enable the necessary code page support on your host.

If you cannot enable this support, a workaround is to use the DB2CODEPAGE keyword in your client's configuration. For more information, see the section on configuring national language support in the DB2 Connect Enterprise Edition for OS/2 and Windows Quick Beginnings.