Configuring debug/syslog operation

  1. To use a syslog server as the destination device for debug messaging, follow these steps:
    1. Enter the logging <syslog-ip-addr> command at the global configuration level to configure the syslog server IP address and enable syslog logging. Optionally, you may also specify the destination subsystem to be used on the syslog server by entering the logging facility command.If no other syslog server IP addresses are configured, entering the logging command enables both debug messaging to a syslog server and the event debug message type. As a result, the switch automatically sends Event Log messages to the syslog server, regardless of other debug types that may be configured.

    2. Re-enter the logging command in Step 1a to configure additional syslog servers. You can configure up to a total of six servers. (When multiple server IP addresses are configured, the switch sends the debug message types that you configure in Step 3 to all IP addresses.)

  2. To use a CLI session on a destination device for debug messaging:
    1. Set up a serial, Telnet, or SSH connection to access the switch's CLI.

    2. Enter the debug destination session command at the manager level.

  3. Enable the types of debug messages to be sent to configured syslog servers, the current session device, or both by entering the debug <debug-type> command and selecting the desired options.

    Repeat this step if necessary to enable multiple debug message types.

    By default, Event Log messages are sent to configured debug destination devices. To block Event Log messages from being sent, enter the no debug event command.

  4. If necessary, enable a subset of Event Log messages to be sent to configured syslog servers by specifying a severity level, a system module, or both using the following commands:
    switch(config)# logging severity <debug | major | error | warning | info>
    switch(config)# logging system-module <system-module>

    To display a list of valid values for each command, enter logging severity or logging system-module followed by ? or pressing the Tab key.

  5. If you configure system-module, severity-level values, or both to filter Event Log messages, when you finish troubleshooting, you may want to reset these values to their default settings so that the switch sends all Event Log messages to configured debug destinations (syslog servers, CLI session, or both).
    To remove a configured setting and restore the default values that send all Event Log messages, enter one or both of the following commands:
    switch(config)# no logging severity <debug | major | error | warning | info>
    switch(config)# no logging system-module <system-module>


If you configure a severity-level, system-module, logging destination, or logging facility value and save the settings to the startup configuration (For example, by entering the write memory command), the debug settings are saved after a system reboot (power cycle or reboot) and re-activated on the switch. As a result, after switch startup, one of the following situations may occur:

  • Only a partial set of Event Log messages may be sent to configured debug destinations.

  • Messages may be sent to a previously configured syslog server used in an earlier debugging session.