PLANET XGS3-24040 - Manual (Page 567)

Chapter 66 Monitor and Debug
66-3
66.6 Debug
All the protocols switch supports have their corresponding debug commands. The users can use the
information from debug commands for troubleshooting. Debug commands for their corresponding protocols
will be introduced in the later chapters.
66.7 System log
66.7.1 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
 Log output from four directions (or log channels) of the Console, Telnet terminal and monitor, log
buffer zone, and log host.
 The log information is classified to four level of severities by which the information will be filtered
 According to the severity level the log information can be auto outputted to corresponding log
channel.
66.7.1.1 Log Output Channel
So far the system log can be outputted the log information through four channels:
 Through Console port to the local console
 Output the log information to remote Telnet terminal or monitor, this function is good for remote
maintenance
 Assign a proper log buffer zone inside the switch, for record the log information permanently or
temporarily
 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 system operation and detecting
abnormal states.