Logging command

At the global configuration level, the loggingcommand allows you to enable debug logging on specified syslog servers and select a subset of Event Log messages to send for debugging purposes according to:

  • Severity level

  • System module

By specifying both a severity level and system module, you can use both configured settings to filter the Event Log messages you want to use to troubleshoot switch or network error conditions.


After you configure a syslog server and a severity level and/or system module to filter the Event Log messages that are sent, if you save these settings to the startup configuration file by entering the write memory command, these debug and logging settings are automatically re-activated after a switch reboot or power recycle. The debug settings and destinations configured in your previous troubleshooting session will then be applied to the current session, which may not be desirable.

After a reboot, messages remain in the Event Log and are not deleted. However, after a power recycle, all Event Log messages are deleted.

If you configure a severity level, system module, or both to temporarily filter Event Log messages, be sure to reset the values to their default settings by entering the no form of the following commands to ensure that Event Log messages of all severity levels and from all system modules are sent to configured syslog servers:

switch(config)# no logging severity <debug | major | error | warning | info>
switch(config)# no logging system-module <system-module>