3com WX4400 3CRWX440095A User Manual

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Running Traces
633
About Trace Results
The trace commands use the underlying logging mechanism to deliver 
trace messages. Trace messages are generated with the debug severity 
level. By default, the only log target that receives debug-level messages is 
the volatile trace buffer. (To see the contents of the trace buffer, see 
“Displaying Trace Results” on page 633.)
The volatile trace buffer receives messages for all log severities when any 
trace area is active. However, if no trace area is active, no messages are 
sent to the trace buffer regardless of their severity. If you do not enable 
trace commands, the trace buffer is effectively disabled.
Because traces use the logging facility, any other logging target can be 
used to capture trace messages if its severity is set to debug. However, 
since tracing can be voluminous, 3Com discourages this in practice. To 
enable trace output to the console, enter the command set log console 
severity debug
.
If you attempt to send trace output to a Telnet session, be aware that 
tracing is disabled for areas processing packets that might be associated 
with the Telnet session.
Displaying Trace
Results
To view the output of currently running trace commands, use the 
following command:
display log trace [{+|-|/}number-of-messages
[facility facility-name] [matching string
[severity severity-level
For example, the following command displays a trace log of error-level 
events: 
WX1200# display log trace severity error
KERNEL Jan 15 23:08:10 ERROR duplicate IP address 
10.7.122.102 sent from link address 00:05:5d:45:ae:cd
To display a specific number of trace log messages, you must enter a plus 
sign (+), minus sign (-), or slash (/) before the number. These characters 
filter the messages displayed as follows: 
„
+number-of-messages — Displays the specified number of log entries, 
starting with the oldest in the log.
„
-number-of-messages — Displays the specified number of entries, 
starting with the newest in the log.