The event command controls the generation and notification of threshold crossing events configured with the alarm command. When a threshold crossing event is triggered, the rmon event configuration optionally specifies whether an entry in the RMON-MIB log table be created to record the occurrence of the event. It can also specify whether an SNMP notification (trap) be generated for the event. There are two notifications for threshold crossing events, a rising alarm and a falling alarm.
Creating an event entry in the RMON-MIB log table does not create a corresponding entry in the event logs. However, when the event is set to trap the generation of a rising alarm or falling alarm notification creates an entry in the event logs and that is distributed to whatever log destinations are configured: console, session, memory, file, syslog, or SNMP trap destination. The logger message includes a rising or falling threshold crossing event indicator, the sample type (absolute or delta), the sampled value, the threshold value, the rmon-alarm-id, the associated rmon-event-id and the sampled SNMP object identifier.
The alarm command configures an entry in the RMON-MIB alarm table. The alarm command controls the monitoring and triggering of threshold crossing events. In order for notification or logging of a threshold crossing event to occur there must be at least one associated rmon event configured.
The agent periodically takes statistical sample values from the MIB variable specified for monitoring and compares them to thresholds that have been configured with the alarm command. The alarm command configures the MIB variable to be monitored, the polling period (interval), sampling type (absolute or delta value), and rising and falling threshold parameters. If a sample has crossed a threshold value, the associated ‛event’ is generated.
Preconfigured CLI threshold commands are available. Preconfigured commands hide some of the complexities of configuring RMON alarm and event commands and perform the same function. In particular, the preconfigured commands do not require the user to know the SNMP object identifier to be sampled. The preconfigured threshold configurations include memory warnings and alarms and compact flash usage warnings and alarms.
To create events, use the following CLI:
config>system>thresholds# cflash-cap-warn cf1-B: rising-threshold 2000000 falling-threshold 1999900 interval 240 trap startup-alarm either
— config>system>thresholds# memory-use-alarm rising-threshold 50000000 falling-threshold 45999999 interval 500 both startup-alarm either
— config>system>thresh# rmon
— config>system>thresh>rmon# event 5 both description "alarm testing" owner "Timos CLI"
The following example shows the command output:
A:ALA-49>config>system>thresholds# info
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rmon
event 5 description "alarm testing" owner "Timos CLI"
exit
cflash-cap-warn cf1-B: rising-threshold 2000000 falling-threshold
1999900 interval 240 trap
memory-use-alarm rising-threshold 50000000 falling-threshold
45999999 interval 500
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A:ALA-49>config>system>thresholds#