2.1.2 Commonly Used Rmon Groups - H3C S5100-SI Operation Manual

probe function. Through the RMON-capable SNMP agents running on the Ethernet switch, an
NMS can obtain the information about the total traffic, error statistics and performance statistics of
the network segments to which the ports of the managed network devices are connected. Thus,
the NMS can further manage the networks.

2.1.2 Commonly Used RMON Groups

1. Event group
Event group is used to define the indexes of events and the processing methods of the events. The
events defined in an event group are mainly used by entries in the alarm group and extended
alarm group to trigger alarms.
You can specify a network device to act in one of the following ways in response to an event:
Logging the event
Sending traps to the NMS
Logging the event and sending traps to the NMS
No processing
2. Alarm group
RMON alarm management enables monitoring on specific alarm variables (such as the statistics
of a port). When the value of a monitored variable exceeds the threshold, an alarm event is
generated, which then triggers the network device to act in the way defined in the events. Events
are defined in event groups.
With an alarm entry defined in an alarm group, a network device performs the following operations
accordingly:
Sampling the defined alarm variables periodically
Comparing the samples with the threshold and triggering the corresponding events if the
former exceed the latter
3. Extended alarm group
With extended alarm entry, you can perform operations on the samples of alarm variables and
then compare the operation results with the thresholds, thus implement more flexible alarm
functions.
With an extended alarm entry defined in an extended alarm group, the network devices perform
the following operations accordingly:
Sampling the alarm variables referenced in the defined extended alarm expressions
periodically
Performing operations on the samples according to the defined expressions
Comparing the operation results with the thresholds and triggering corresponding events if
the operation result exceeds the thresholds.
4. History group
After a history group is configured, the Ethernet switch collects network statistics information
periodically and stores the statistics information temporarily for later use. A history group can
provide the history data of the statistics on network segment traffic, error packets, broadcast
packets, and bandwidth utilization.
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