When a device is running, the log module on the device records user operations and events into log messages. Log messages allow you to learn about the running status of the device, analyze the network situations, locate faults, as well as diagnose and maintain the device.
You can log in to the device through console port or Telnet, run the display logbuffer command to view the logs stored in buffer, save logs on the device, and export the logs to a log server using the syslog protocol.
The following methods can help you quickly find out the desired logs:
The Brief information in a log message uniquely identifies a log, so you can search for the Brief information in the manual to find out the desired log, view log description, and learn about the handling method.
The parameters such as time, interface number, process ID, and device name in a log message are variable, so do not use these parameters to search for logs.
Example:
Log message: Apr 27 2014 07:45:35 HUAWEI %%01SHELL/4/LOGIN_FAIL_FOR_INPUT_TIMEOUT(s)[6]:Failed to log in due to timeout.(Ip=10.135.19.157, UserNa me=**, Times=1, AccessType=TELNET, VpnName=)
Search for LOGIN_FAIL_FOR_INPUT_TIMEOUT in the manual, and you can see the log description: After entering a user name or password, a user failed to log in because of a timeout.