SNR S2940-8G-v2, Configuration Manual

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SNR S2940-8G-v2 Switch Configuration Guide
Monitor and Debug
• 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 Ran-
dom 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.
Note: the NVRAM log buffer may not exist on some switches, which only have the SDRAM
log buffer zone.
It is recommended to use the system log server. By configuring the log host on the switch, the
log can be sent to the log server for future examination.
Format and Severity of the Log Information
The log information format is compatible with the BSD syslog protocol, so we can record and
analyze the log by the systlog (system log protect session) on the UNIX/LINUX, as well as syslog
similar applications on PC.
The log information is classified into eight classes by severity or emergency procedure. One
level per value and the higher the emergency level the log information has, the smaller its value will
be. For example, the level of critical is 2, and warning is 4, debugging is leveled at 7, so the critical
is higher than warnings which no doubt is high than debugging. The rule applied in filtering the log
information by severity level is that: only the log information with level equal to or higher than the
threshold will be outputted. So when the severity threshold is set to debugging, all information will
be outputted and if set to critical, only critical, alerts and emergencies will be outputted.
Follow table summarized the log information severity level and brief description.
Note: these severity levels are in accordance with the standard UNIX/LINUX syslog.
Severity Value Description
emergencies 0 System is unusable
alerts 1 Action must be taken immediately
critical 2 Critical conditions
errors 3 Error conditions
warnings 4 Warning conditions
notifications 5 Normal but significant condition
informational 6 Informational messages
debugging 7 Debug-level messages
Right now the switch can generate information of following four levels:
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