SNA Link/iX Node Managers Guide (30291-90507)

114 Chapter5
SNA Link Troubleshooting
The Tracing Facility
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.
Link-Level Tracing
The data link-level protocol is traced by the link driver (for the SDLC
and token ring links) and the module configurator (for the X.25 link).
Link-level tracing is turned on with the
LINKTRACE parameter of the
SNACONTROL START or SNACONTROL TRACEON MPE command, and off
with the SNACONTROL STOP command or the
LINKTRACE parameter of
the SNACONTROL TRACEOFF command. Link-level tracing has two
options: trace all bytes of each link frame (full tracing), and trace only
the first 16 bytes of each link frame (partial tracing). Since full tracing
uses more resources, partial tracing is the recommended default.
Link-level trace output is written to a disk file.
We recommend that you use link-level tracing only for problem-solving
purposes when requested by the HP systems engineer.
The trace file name can be specified as an argument to the
LINKTRACE
parameter when tracing is started. Naming the file this way allows the
contents of the file to be overwritten each time a new trace is started
(no warning is issued). Note that if you start link-level tracing with the
SNACONTROL START command, and specify a name for the trace file, the
file must be written to the SYS account. That is, if you specify an
account name within the trace file name, it must be SYS. If you do not
specify an account name, the file will automatically be written to the
SYS account. This applies only when link-level tracing is started with
the SNACONTROL START command.
You also can let the default name be assigned: NMTC
nnnn .PUB.SYS,
where
nnnn is a number from 0000 through 9999.