Quick Reference Guide

Management | 77
The event variables are:
• 1-65535: An arbitrary number to be used to refer to this event in the Index
• log: Create an entry in the log table. Default none
• trap:SNMP community used if a trap is to be sent (default: public)
• description: Comment describing this entry, <string-max 127 char >
• owner: Entity that configured this entry, <string-max 127 char>
Figure 4-47. RMON Event Thresholds
Figure 4-47, above, depicts the points at which RMON threshold alarms are triggered. The first concept is
that an event occurs when a threshold is crossed — either crossing a rising threshold or crossing a falling
threshold. The other main concept is that a second event of that type cannot occur until the opposite
threshold has been crossed in order to end the period of the first event.
In setting the alarm, you must choose between absolute and delta:
•
absolute — This is an actual value of the selected MIB variable. This choice is better for rate
measurements that vary plus or minus. For example, if a value never falls, the falling threshold will
never be reached, and the rising threshold will only be crossed once.
•
delta — This choice is best with counters that only increment. The previous value of the MIB variable
is subtracted from the current value to determine whether the value is incrementing from its previous
value by the Rising Threshold amount, or by an amount equal to or less than the Falling Threshold
amount.
2
[no] rmon alarm 1-65535
SNMP_OID 5-3600 {
delta |
absolute} rising-threshold
0-4294967295 index
falling-threshold 0-4294967295
index
[owner string]
Global Config Identify the event ID created in Step 1 for which
you want to set [or disable] an alarm, identify
the target MIB, and configure the parameters
that trigger the alarm.
3
show rmon alarms brief Privileged Exec Display a summary of the contents of the
RMON Alarm Table.