ATL Telecom R1-SW Ethernet Switch - Manual (Page 161)

Configuring SNMP and RMON
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To delete an event group, enter the no rmon event command in Global configuration mode:
(config)# no rmon event 10
(config)#
Configuring Alarm Groups
The RMON Alarm group allows you to set an alarm threshold and a sampling interval to
enable the RMON agent to generate alarms on any network segment it monitors. Alarm
thresholds can be based on ‘
absolute ’ or ‘ delta’ values so that you can be notified of rapid spikes
or drops in a monitored value.
Each alarm is linked to an event in the event group. An event defines an action that will be
triggered when the alarm threshold is exceeded.
The alarm group periodically takes statistical samples from variables and compares them to
previously configured thresholds. The Alarm Table stores configuration entries that define a
variable, a polling period, and threshold parameters. If the RMON agents determines that a
sample crosses the threshold values, it generates an event. You can specify rising or falling
thresholds, indicating network faults such as slow throughput or other network-related
performance problems. You specify rising thresholds when you want to be notified that an
alarm has risen above the threshold you specified. You specify falling thresholds when you
want to be notified that the network is behaving normally again. For example, you might
specify a falling threshold of 30 collisions per second to indicate a return to acceptable behavior.
When you configure an alarm condition, you must define the following values:
y The monitoring interval over which data is sampled.
y The variable to be sampled.
y Rising and falling thresholds used to detect when network trouble starts and when it ends.
y The event that takes place when a rising threshold is crossed.
y The event that takes place when a falling threshold is crossed.
An
RMON event is the action that occurs when an associated RMON alarm is triggered. When an
alarm event occurs, it can be configured to generate a log event, a trap to an SNMP network
management station, or both. For information on viewing alarm events in log files.