H3C Technologies H3C MSR 5600 - Manual (Page 134)

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• None—Takes no actions.
Alarm group
The RMON alarm group monitors alarm variables, such as the count of incoming packets (etherStatsPkts)
on an interface. After you create an alarm entry, the RMON agent samples the value of the monitored
alarm variable regularly. If the value of the monitored variable is greater than or equal to the rising
threshold, a rising alarm event is triggered. If the value of the monitored variable is smaller than or equal
to the falling threshold, a falling alarm event is triggered. The action to take on the alarm event is defined
in the event group.
If an alarm entry crosses a threshold multiple times in succession, the RMON agent generates an alarm
event only for the first crossing. For example, if the value of a sampled alarm variable crosses the rising
threshold multiple times before it crosses the falling threshold, only the first crossing triggers a rising alarm
event, as shown in
Figure 45 .
Figure 45 Rising and falling alarm events
Private alarm group
The private alarm group enables you to perform basic math operations on multiple variables, and then
compare the calculation result with the rising and falling thresholds.
The RMON agent uses a private alarm entry as follows:
1. Samples the private alarm variables in the user-defined formula.
2. Processes the sampled values with the formula.
3. Compares the calculation result with the predefined thresholds, and then takes one of the following
actions:
{
Triggers the event associated with the rising alarm event if the result is equal to or greater than
the rising threshold.
{
Triggers the event associated with the falling alarm event if the result is equal to or less than the
falling threshold.
If a private alarm entry crosses a threshold multiple times in succession, the RMON agent generates an
alarm event only for the first crossing. For example, if the value of a sampled alarm variable crosses the
rising threshold multiple times before it crosses the falling threshold, only the first crossing triggers a rising
alarm event. If the count result of the private alarm group overpasses the same threshold multiple times,
only the first one can cause an alarm event. In other words, the rising alarm and falling alarm alternate.