The log module of the host software records operations on a device and events that occur on a device. The recorded operations and events are log messages.
Log messages provide evidence for diagnosing and maintaining a system. Log messages reflect the operating status of a device and are used to analyze the conditions of a network and to find out the causes of network failure or faults.
After logging in to a device through the console port or in telnet mode, you can display log messages stored on the log buffer by using the display logbuffer command and save the log messages on the device. Log messages can be output to a log server with the support of the SYSLOG protocol.