Logging Levels; Enabling Logging For Telnet Or Ssh - Cisco Nexus 9000 Series Troubleshooting Manual

Troubleshooting Tools and Methodology
You can use syslog to store a chronological log of system messages locally or to send this information to a
central syslog server. The syslog messages can also be sent to the console for immediate use. These messages
can vary in detail depending on the configuration that you choose.
The syslog messages are categorized into seven severity levels from debug to critical events. You can limit
the severity levels that are reported for specific services within the device. For example, you might want to
report debug events only for the OSPF service but record all severity level events for the BGP service.
Log messages are not saved across system reboots. However, a maximum of 100 log messages with a severity
level of critical and below (levels 0, 1, and 2) are saved in NVRAM. You can view this log at any time with
the show logging nvram command.

Logging Levels

Cisco NX-OS supports the following logging levels:
• 0-emergency
• 1-alert
• 2-critical
• 3-error
• 4-warning
• 5-notification
• 6-informational
• 7-debugging
By default, the device logs normal but significant system messages to a log file and sends these messages to
the system console. Users can specify which system messages should be saved based on the type of facility
and the severity level. Messages have a time stamp to enhance real-time debugging and management.

Enabling Logging for Telnet or SSH

System logging messages are sent to the console based on the default or configured logging facility and
severity values.
• To disable console logging, use the no logging console command in configuration mode.
• To enable logging for Telnet or SSH, use the terminal monitor command in EXEC mode.
• When logging to a console session is disabled or enabled, that state is applied to all future console
The no logging console command disables console logging and is enabled by default.
switch(config)# no logging console
sessions. If a user exits and logs in again to a new session, the state is preserved. However, when logging
to a Telnet or SSH session is enabled or disabled, that state is applied only to that session. The state is
not preserved after the user exits the session.
Cisco Nexus 9000 Series NX-OS Troubleshooting Guide, Release 7.x
Logging Levels
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