This section lists the most common symptoms of connection problems encountered when using DB2 Connect. In each case, you are provided with:

• A combination of a message number and a return code (or protocol specific return code) associated with that message. Each message and return code combination has a separate heading, and the headings are ordered by message number, and then by return code.
• A symptom is provided, usually in the form of a sample message listing.
• A suggested solution is provided, indicating the probable cause of the error. In some cases more than one suggested solution may be provided.

SQL1403N

Symptom: SQL1403N The username and/or password supplied is incorrect.

Solution: User fails to authenticate at the DB2 Connect workstation. Determine whether the user is supposed to be authenticated at the DB2 Connect workstation.

If yes, make sure that the correct password is provided on the CONNECT statement if necessary.

If no, the system database directory entry must have been incorrectly cataloged using AUTHENTICATION SERVER (this is the default if AUTHENTICATION is not specified explicitly). If this is the case, then re-catalog the entry using AUTHENTICATION DCS or CLIENT.

Password is not available to send to the target server database. If the system database directory entry is cataloged using AUTHENTICATION DCS, then a password has to be flowed from the DB2 Client to the target server database. On certain platforms, for example AIX, the password can only be obtained if it is provided on the CONNECT statement.

SQL5043N

Symptom: Support for one or more communications protocols failed to start successfully. However, core database manager functionality started successfully.

Perhaps the TCP/IP protocol is not started on the DB2 Connect gateway. There may have been a successful client connection previously

Solution: This warning is a symptom which signals that DB2 Connect, acting as a gateway for remote clients, is having trouble handling one or more client communication protocols. These protocols can be TCP/IP, APPC and others, and usually the message indicates that one of the communications protocols defined to DB2 Connect is not configured properly.

Often the cause may be that the DB2COMM profile variable is not defined, or is defined incorrectly. Generally, the problem is the result of a mismatch between the DB2COMM variable and names defined in the database manager configuration (for example, svcename or tpname).

One possible scenario is having a previously successful connection, then getting the SQL5043 error message, while none of the configuration has changed. This could occur using the TCP/IP protocol, when the remote system abnormally terminates the connection for some reason. When this happens, a connection may still appear to exist on the client, and it may become possible to restore the connection without further intervention by issuing the commands shown below.

Most likely, one of the clients connecting to the gateway still has a handle on the TCP/IP port. On each client machine that is connected to the gateway.

SQL30061

Symptom: Connecting to the wrong host or AS/400 database server location - no target database can be found.

Solution: The wrong server database name may be specified in the DCS directory entry. When this occurs, SQLCODE -30061 is returned to the application.

Check the DB2 node, database, and DCS directory entries. The target database name field in the DCS directory entry must correspond to the name of the database based on the platform.

SQL30081 with Return Code 79

Symptom: SQL30081N A communication error has been detected.

Communication protocol being used: "TCP/IP". Communication API being used: "SOCKETS".

Location where the error was detected: "". Communication function detecting the error:

"connect". Protocol specific error code(s): "79", "*", "*". 
SQLSTATE=08001

Solution: This error can occur in the case of a remote client failing to connect to a DB2 Connect gateway. It can also occur when connecting from the DB2 Connect gateway to a host.

The DB2COMM profile variable may set incorrectly on the DB2 Connect gateway. Check this. For example, the command db2set db2comm=tcpip should appear in sqllib/db2profile when running DB2 Extended Enterprise Edition on AIX.

There may be a mismatch between the TCP/IP service name and/or port number specifications at the DB2 client and the DB2 Connect gateway. Verify the entries in the TCP/IP services files on both machines.