SNA Link/iX Node Managers Guide (30291-90009)

Chapter 5 109
SNA Link Troubleshooting
The Tracing Facility
NOTE Regardless of whether you specify a trace file name or let the default
name be assigned, the trace file that is opened when tracing is started
is used until tracing is stopped. This means that if the file becomes full
before tracing is stopped, the current contents of the file are
overwritten with the new trace information, starting at the beginning
of the file (no warning is issued). You should keep this in mind if you
usually run tracing for long periods without stopping. If you want to
keep the contents of a trace file from being written over, stop tracing
before the file is full, and then restart it.
The trace file can be formatted through the NMDUMP utility. Using
NMDUMP for SNA links (including examples of the SDLC link and
X.25 link tracing formats) is described later in this chapter.
More-detailed information about NMDUMP is contained in Using the
Node Management Services Utilities.
NOTE Although the format of the default trace file name is the same for all
types of tracing, the same default file name will not be assigned for
more than one trace. This is because the default trace file name is
automatically assigned in numerical order. For example, suppose the
last default trace file name assigned was NMTC0004.PUB.SYS. If you
started SNA Transport intrinsic tracing, and did not specify a trace file
name, the default name NMTC0005.PUB.SYS would be assigned. Then, if
you started SNA Transport node tracing without specifying a trace file
name, the default name NMTC0006.PUB.SYS would be assigned. Finally,
if you started link-level tracing, and did not specify a file name, the
default name NMTC0007.PUB.SYS would be assigned.
Remember, this applies only when you are using the default file-naming
scheme.