Enabling All-System Diagnostics; Redirecting Debug And Error Message Output; Using The Crashinfo File - Cisco 2950G 24 - Catalyst Switch Software Configuration Manual

Chapter 28 Troubleshooting

Enabling All-System Diagnostics

Beginning in privileged EXEC mode, enter this command to enable all-system diagnostics:
Switch# debug all
Because debugging output takes priority over other network traffic, and because the debug all privileged
Caution
EXEC command generates more output than any other debug command, it can severely diminish switch
performance or even render it unusable. In virtually all cases, it is best to use more specific debug
commands.
The no debug all privileged EXEC command disables all diagnostic output. Using the no debug all
command is a convenient way to ensure that you have not accidentally left any debug commands
enabled.

Redirecting Debug and Error Message Output

By default, the network server sends the output from debug commands and system error messages to the
console. If you use this default, you can use a virtual terminal connection to monitor debug output
instead of connecting to the console port.
Possible destinations include the console, virtual terminals, internal buffer, and UNIX hosts running a
syslog server. The syslog format is compatible with 4.3 Berkeley Standard Distribution (BSD) UNIX
and its derivatives.
Note Be aware that the debugging destination you use affects system overhead. Logging messages to the
console produces very high overhead, whereas logging messages to a virtual terminal produces less
overhead. Logging messages to a syslog server produces even less, and logging to an internal buffer
produces the least overhead of any method.

Using the crashinfo File

The crashinfo file saves information that helps Cisco technical support representatives to debug
problems that caused the IOS image to fail (crash). The switch writes the crash information to the
console at the time of the failure, and the file is created the next time you boot the IOS image after the
failure (instead of while the system is failing).
The information in the file includes the IOS image name and version that failed, a dump of the processor
registers, and a stack trace. You can provide this information to the Cisco technical support
representative by using the show tech-support privileged EXEC command.
All crashinfo files are kept in this directory on the Flash file system:
flash:/crashinfo/crashinfo_n where n is a sequence number.
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Catalyst 2950 Desktop Switch Software Configuration Guide
Using the crashinfo File
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