Cisco Nexus 5000 Series Switch CLI Software Configuration Guide, NX-OS 4.0(1a)N1 (OL-16597-01, January 2009)

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Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
OL-16597-01
Chapter 28 Configuring RMON
Configuration Guidelines and Limitations
When you create an alarm, you specify the following parameters:
• MIB object to monitor
• Sampling interval—The interval that the Cisco Nexus 5000 Series switch uses to collect a sample
value of the MIB object.
• The sample type—Absolute samples take the current snapshot of the MIB object value. Delta
samples take two consecutive samples and calculate the difference between them.
• Rising threshold—The value at which the Cisco Nexus 5000 Series switch triggers a rising alarm or
resets a falling alarm.
• Falling threshold—The value at which the Cisco Nexus 5000 Series switch triggers a falling alarm
or resets a rising alarm.
• Events—The action that the Cisco Nexus 5000 Series switch takes when an alarm (rising or falling)
triggers.
Note Use the hcalarms option to set an alarm on a 64-bit integer MIB object.
For example, you can set a delta type rising alarm on an error counter MIB object. If the error counter
delta exceeds this value, you can trigger an event that sends an SNMP notification and logs the rising
alarm event. This rising alarm will not occur again until the delta sample for the error counter drops
below the falling threshold.
Note The falling threshold must be less than the rising threshold.
RMON Events
You can associate a particular event to each RMON alarm. RMON supports the following event types:
• SNMP notification—Sends an SNMP risingAlarm or fallingAlarm notification when the associated
alarm triggers.
• Log—Adds an entry in the RMON log table when the associated alarm triggers.
• Both—Sends an SNMP notification and adds an entry in the RMON log table when the associated
alarm triggers.
You can specify a different even for a falling alarm and a rising alarm.
Configuration Guidelines and Limitations
RMON has the following configuration guidelines and limitations:
• You must configure an SNMP user an notification receiver to use the SNMP notification event type.
• You can only configure an RMON alarm on a MIB object that resolves to an integer.