Microsens MS453490M Management Guide - Manual (Page 394)

C HAPTER 15 | Basic Administration Protocols
Remote Monitoring
– 394 –
The switch supports mini-RMON, which consists of the Statistics, History,
Event and Alarm groups. When RMON is enabled, the system gradually
builds up information about its physical interfaces, storing this information
in the relevant RMON database group. A management agent then
periodically communicates with the switch using the SNMP protocol.
However, if the switch encounters a critical event, it can automatically send
a trap message to the management agent which can then respond to the
event if so configured.
C ONFIGURING RMON
A LARMS
Use the Administration > RMON (Configure Global - Add - Alarm) page to
define specific criteria that will generate response events. Alarms can be
set to test data over any specified time interval, and can monitor absolute
or changing values (such as a statistical counter reaching a specific value,
or a statistic changing by a certain amount over the set interval). Alarms
can be set to respond to rising or falling thresholds. (However, note that
after an alarm is triggered it will not be triggered again until the statistical
value crosses the opposite bounding threshold and then back across the
trigger threshold.
CLI R EFERENCES
◆ "Remote Monitoring Commands" on page 575
C OMMAND U SAGE
◆ If an alarm is already defined for an index, the entry must be deleted
before any changes can be made.
P ARAMETERS
These parameters are displayed:
◆ Index – Index to this entry. (Range: 1-65535)
◆ Variable – The object identifier of the MIB variable to be sampled.
Only variables of the type etherStatsEntry.n.n may be sampled.
Note that etherStatsEntry.n uniquely defines the MIB variable, and
etherStatsEntry.n.n defines the MIB variable, plus the etherStatsIndex.
For example, 1.3.6.1.2.1.16.1.1.1.6.1 denotes
etherStatsBroadcastPkts, plus the etherStatsIndex of 1.
◆ Interval – The polling interval. (Range: 1-31622400 seconds)
◆ Sample Type – Tests for absolute or relative changes in the specified
variable.
■
Absolute – The variable is compared directly to the thresholds at
the end of the sampling period.
■
Delta – The last sample is subtracted from the current value and
the difference is then compared to the thresholds.
◆ Rising Threshold – If the current value is greater than or equal to the
rising threshold, and the last sample value was less than this threshold,
then an alarm will be generated. After a rising event has been