H3C Technologies H3C Intelligent Management Center - Manual (Page 656)

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When an alarm is cleared or recovered, IMC removes the alarm instance from the Real-Time Alarms and
Root Alarms views. The alarm is visible in the All Alarms view until it is removed from the alarm database
during the next Data Export, which is 2:00am daily by default.
The clearing or recovering of an event can occur manually as when an operator chooses the Recover
action for an alarm. In addition, an alarm can be cleared automatically. Automatic clearing is done
when an event is received by IMC and there is a rule, either system or user defined that distinguishes this
event as the resolution for a specified alarm. In fact, many MIBs include resolution traps along with traps
that indicate failures.
The second option is to delete it. H3C does not recommend this option because deleting an alarm
removes it from the alarm database and along with it the ability to report on it. Alarms are a valuable
data source for performance management of the network infrastructure. You can schedule regular
exports of the alarm database to retain alarm histories. Operators should consider carefully policies for
retaining and for deleting alarms. For more information about the data export capabilities, see " Data
export ."
Clearing or recovering alarms is an important function of IMC and incident management in IT
organizations. Alarms can be cleared from the alarm Actions navigation tree located on the right of the
Alarm Details page. This can be accessed from all of the alarm browse views that IMC offers. For more
information about clearing alarms, " Alarm actions in the alarm details page ."
Trap management
An SNMP trap is a message that is generated by an SNMP network device and sent to a management
system for processing. A trap can indicate an error condition and its resolution. Additionally, a trap can
also be informational. Traps are a proactive source of real time information on the health and status of
the network infrastructure. Traps are effective for monitoring failures in real time because SNMP traps are
messages sent by managed devices to management systems such as IMC.
IMC lets you receive traps from all SNMP managed devices and to review, filter, and generate alarms
and notifications based on the traps received.
Trap management is most effective when all devices in the network infrastructure are configured to
forward traps to IMC and IMC is configured to manage all of the devices that are configured to forward
traps to it. Traps that IMC receives from unmanaged devices are (by default) filtered out.
To effectively use IMC as a trap destination and a source for managing and displaying trap information,
you must first configure all devices to forward traps to IMC. Refer to each vendor's support
documentation for information on how to configure their devices to forward traps to a management
system. You must also add all devices (trap sources) to IMC and configure IMC to receive traps from them
using the IMC auto discovery feature.
For more information about adding and managing devices in IMC and specifically auto discovery, see
"
5 Resource management ." For information on the filtering out traps from unmanaged devices, see
" Modifying Trap Filter Configuration of Devices not in IMC ."
IMC simplifies the process of configuring SNMP settings in IMC when adding devices to IMC through the
use of SNMP templates. SNMP templates lets you save one or more SNMP configurations, which can
then be applied to devices during discovery or when adding devices manually. For more information
about using SNMP templates, see " SNMP templates ."