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2.2.9 System log
2.2.9.1 System Log Introduction
The system log takes all information output under it control, while making detailed
catalogue, so to select the information effectively. Combining with Debug programs, it will
provide a powerful support to the network administrator and developer in monitoring the
network operation state and locating the network failures.
The switch system log has following characteristics
z
Log output from four directions (or log channels) of the Console, Telnet terminal
and monitor, log buffer zone, and log host.
z
The log information is classified to four level of severities by which the
information will be filtered
z
According to the severity level the log information can be auto outputted to
corresponding log channel.
2.2.9.1.1 Log Output Channel
So far the system log can be outputted the log information through four channels
z
Through Console port to the local console
z
Output the log information to remote Telnet terminal or monitor, this function is
good for remote maintenance.
z
Assign a proper log buffer zone inside the switch, for record the log information
permanently or temporarily
z
Configure the log host, the log system will directly send the log information to
the log host, and save it in files to be viewed at any time
Among above log channels, users rarely use the console monitor, but will commonly
choose the Telnet terminal to monitor the system operation status. However information
outputted from these channels are of low traffic capacity and can not be recorded for later
view. The other two channels---the log buffer zone and log host channel are two
important channels
SDRAM (Synchronous Dynamic Random Access Memory) and NVRAM (Non
Vulnerable Random Access Memory) is provided inside the switch as two part of the log
buffer zone, The two buffer zone record the log information in a circuit working pattern,
namely when log information need to be recorded exceeds the buffer size, the oldest log
information will be erased and replaced by the new log information, information saved in
NVRAM will stay permanently while those in SDRAM will lost when the system restarts or
encounter an power failure. Information in the log buffer zone is critical for monitoring the
