Cabletron Systems SPECTRUM, User Manual

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Basic Alarm Configuration
3-10 Viewing an Alarm Log
Viewing an Alarm Log
The ability to create a log of alarm events is provided by the Event group of the
RMON MIB. If you have selected the Log option for any of your alarms, and you
wish to view the resulting log, you can do so by using MIBTree or any similar
SNMP-based MIB tool to query the RMON MIB’s logTable.
Each entry in the logTable (logEntry) contains the following objects:
logEventIndex
The value of this object reflects the index number assigned to the event whose
occurrences you have chosen to log. (The “event” is the device’s response to the
“alarm” — if an alarm threshold is crossed, the event specifies what action will be
taken. The Basic Alarm application allows you to create three kinds of events:
those that create a log, those that generate a trap, and those that do both.) The
value of this index number won’t tell you which interface the alarm instances
occurred on; however, it will help you to figure out which values of the logIndex,
logTime, and logDescription OIDs go together, as this value becomes part of the
instance assigned to each object in the table.
logIndex
The value of this object uniquely identifies each alarm occurrence that is stored in
a log entry. In combination with the logEventIndex value described above, the
logIndex provides the instance values assigned to each table object; use these
instance values to sort out individual log entries. For example, the values of all
logTable OIDs with the instance 7.1 apply to the first occurrence of alarm index 7;
the values of all OIDs with the instance 7.2 apply to the second occurrence of
alarm index 7; and so on.
!
CAUTION
Making sense of a logTable entry by viewing its values straight from the MIB is a tricky
business that requires a good understanding of MIBs and MIB objects, a good
understanding of the RMON alarm and event functionality, and a little bit of luck:
individual returned MIB values must first be sorted into complete entries; each entry
must then be matched to the appropriate interface. This process will require some patience,
especially if you are viewing the logTable for a 7C0x chassis with many installed
interfaces, many of which have enabled alarms. Future releases of SPMA will include
more advanced alarm functionality, including the ability to view alarm logs in an
easy-to-read format.
TIP
Use the instance values assigned to each table object (logEventIndex.logIndex) to arrange
the returned values into complete entries; then, view each entry’s logDescription to match
the entry to a 7C0x interface. See logDescription, below, for more information.