Cisco Systems IE 2000 Enabling Debugging on a Specific Feature, Enabling All-System Diagnostics

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Cisco IE 2000 Switch Software Configuration Guide
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Chapter 46 Troubleshooting
How to Troubleshoot
Enabling Debugging on a Specific Feature
Caution Because debugging output is assigned high priority in the CPU process, it can render the system
unusable. For this reason, use debug commands only to troubleshoot specific proble ms or during
troubleshooting sessions with Cisco technical support staff. It is best to use debug commands during
periods of lower network traffic and fewer users. Debugging during these periods decrease s the
likelihood that increased debug command processing overhead will affect system use.
All debug commands are entered in privileged EXEC mode, and most debug commands take no
arguments. For example, beginning in privileged EXEC mode, enter this c ommand to enable the
debugging for Switched Port Analyzer (SPAN):
Switch# debug span-session
The switch continues to generate output until you enter the no form of the command.
If you enable a debug command and no output appears, consi der these possibilities:
• The switch might not be properly configured to generate the type of traffic you want to monitor. Use
the show running-config command to check its configuration.
• Even if the switch is properly configured, it might not generate the type of traffic you want to
monitor during the particular period that debugging is enabled. Depending on the featur e you are
debugging, you can use commands such as the TCP/IP ping command to generate net work traffic.
To disable debugging of SPAN, enter this command in privileged EXEC mode:
Switch# no debug span-session
Alternately, in privileged EXEC mode, you can enter the undebug form of the command:
Switch# undebug span-session
To display the state of each debugging option, enter this command in privileged EXEC mode:
Switch# show debugging
Enabling All-System Diagnostics
Beginning in privileged EXEC mode, enter this command to enable all-system diagnostics:
Switch# debug all
Caution Because debugging output takes priority over other network traffic, and because the debug all privileged
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.