139
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.
Sample types for the alarm group and the private alarm group
The RMON agent supports the following sample types:
•
absolute
—RMON compares the value of the monitored variable with the rising and falling
thresholds at the end of the sampling interval.
•
delta
—RMON subtracts the value of the monitored variable at the previous sample from the
current value, and then compares the difference with the rising and falling thresholds.
Protocols and standards
•
RFC 4502,
Remote Network Monitoring Management Information Base Version 2
•
RFC 2819,
Remote Network Monitoring Management Information Base Status of this Memo
Configuring the RMON statistics function
RMON implements the statistics function through the Ethernet statistics group and the history group.
The Ethernet statistics group provides the cumulative statistic for a variable from the time the
statistics entry is created to the current time. For more information about the configuration, see
"Creating an RMON Ethernet statistics entry."
The history group provides statistics that are sampled for a variable for each sampling interval. The
history group uses the history control table to control sampling, and it stores samples in the history
table. For more information about the configuration, see "
Creating an RMON history control entry
."
Creating an RMON Ethernet statistics entry
Step
Command
Remarks
1.
Enter system
view.
system-view
N/A
2.
Enter Ethernet
interface view.
interface interface-type
interface-number
N/A
3.
Create an RMON
Ethernet statistics
entry.
rmon statistics
entry
-
number
[
owner
text
]
By default, no RMON Ethernet statistics entry
exists.
You can create only one RMON statistics
entry for an Ethernet interface.
You can create a maximum of 100 RMON
statistics entries on a device. When the limit
is reached, you cannot add new entries.
Creating an RMON history control entry
You can configure multiple history control entries for one interface, but you must make sure their
entry numbers and sampling intervals are different.