Sources of diagnostic information

Many problems with the X.25 NPSI server are the result of configuration faults. Check the following configuration files:

BEGINROUTES statements, DEVICE and LINK in PROFILE.TCPIP
The X.25 NPSI server configuration data set
VTAM® APPL definition for the X.25 NPSI server
NPSI definitions
VTAM SWNET definitions for NPSI

The primary diagnostic information source is the activity log produced by the X.25 NPSI server. Messages appear in the MVS™ system log, and can also be captured into a separate data set by including a SYSPRINT DD statement in the X.25 NPSI cataloged procedure. Normal logging records virtual circuit establishment and termination.

Additional information can be recorded about VC activity by setting the TRACE CONTROL option in the X.25 NPSI server configuration data set. This level is sufficient for almost all problem situations; interpretation of the data requires knowledge of X.25 NPSI packet formats. Tracing of the contents of IP datagrams sent to and received from NPSI is provided by the MVS CTRACE option. For details on using the CTRACE option, see TCP/IP services traces and IPCS support.

VTAM buffer traces and NPSI X.25 line traces can also be useful in diagnosing difficult problem situations.

You can perform traces on the X.25 LINKNAME using the TCPIP PKTTRACE command or on the SNA LU name using the VTAM buffer trace command. See TCP/IP services traces and IPCS support, for details about how to use the IP packet trace facility.