53-2
of the network segments to which the ports of the managed
network devices are connected. Thus, the NMS can further manage the networks.
Commonly
E
nts. The
arm
u
ng ways in response to an event:
z
Sending traps to the NMS
the event and sending traps to the NMS
A
anagement enables monitoring on specific alarm variables (such as the statistics of a
.
z
Sampling the defined alarm variables periodically
ples with the threshold and triggering the corresponding events if the former
E
hresholds, thus implement more flexible alarm functions.
z
he defined extended alarm expressions periodically
z
Performing operations on the samples according to the defined expressions
the operation results with the thresholds and triggering corresponding events if the
H
is configured, the Ethernet switch collects network statistics information
ata management function, you can configure network devices to collect history data,
statistics and performance statistics
Used RMON Groups
vent group
Event group is used to define the indexes of events and the processing methods of the eve
events defined in an event group are mainly used by entries in the alarm group and extended al
gro p to trigger alarms.
You can specify a network device to act in one of the followi
z
Logging the event
z
Logging
z
No processing
larm group
RMON alarm m
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:
z
Comparing the sam
exceed the latter
xtended alarm group
With extended alarm entry, you can perform operations on the samples of alarm variables and then
compare the operation results with the t
With an extended alarm entry defined in an extended alarm group, the network devi
followin
ces perform the
g operations accordingly:
Sampling the alarm variables referenced in t
z
Comparing
operation result exceeds the thresholds.
istory group
After a history group
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.
With the history d
sample and store data of a specific port periodically.
