Steps for diagnosing TCP/IP clients unable to connect

Determine why TCP/IP clients are unable to connect.

Perform the following steps:

1. Verify that the listener is active by logging on to CICS®, and then issue a CEMT I TASK command. Make sure that the listener name appears in the task list.
2. Verify that the listener is listening on the correct port number by issuing a NETSTAT CONN command, and then check that the listener has the correct port in listen status. Verify that clients are trying to connect to this port and to the correct IP address.
3. Check the ERRORTD log and verify that the EZY1291I message has been issued. If it has not been issued, look for messages that indicate a failure.
4. If message EZY1365E is issued, then ensure that the value specified for the MAXFILEPROC is larger than the listener's NUMSOCK value. Also, ensure that the client's user ID FILEPROCMAX setting is appropriately specified. For more information about how MAXFILEPROC affects tuning applications, see z/OS UNIX System Services Planning.

   For more information about the FILEPROCMAX specification, see the documentation provided for the SAF product in use on your system. If using RACF®, this can be found in z/OS Security Server RACF Security Administrator's Guide.