Configuring RMON

This chapter describes how to configure the remote monitoring (RMON) feature on Cisco NX-OS devices.

This chapter contains the following sections:

About RMON

RMON is a Simple Network Management Protocol (SNMP) Internet Engineering Task Force (IETF) standard monitoring specification that allows various network agents and console systems to exchange network monitoring data. Cisco NX-OS supports RMON alarms, events, and logs to monitor Cisco NX-OS devices.

An RMON alarm monitors a specific management information base (MIB) object for a specified interval, triggers an alarm at a specified threshold value (threshold), and resets the alarm at another threshold value. You can use alarms with RMON events to generate a log entry or an SNMP notification when the RMON alarm triggers.

RMON is enabled by default, but no alarms are configured in Cisco NX-OS. You can configure RMON alarms by using the CLI or an SNMP-compatible network management station.

RMON Alarms

You can set an alarm on any MIB object that resolves into an SNMP INTEGER type. The specified object must be an existing SNMP MIB object in standard dot notation (for example, 1.3.6.1.2.1.2.2.1.14 represents ifInOctets.14).

When you create an alarm, you specify the following parameters:

  • MIB object to monitor.

  • Sampling interval—The interval that the device uses to collect a sample value of the MIB object.

  • 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 device triggers a rising alarm or resets a falling alarm.

  • Falling threshold—The value at which the device triggers a falling alarm or resets a rising alarm.

  • Events—The action that the device 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.


Note
You may choose to use the default RMON events template configuration or you can delete these entries and create new RMON events. Until you create RMON alarm configurations, no alarms will be triggered by these configurations.

High Availability for RMON

Cisco NX-OS supports stateless restarts for RMON. After a reboot or supervisor switchover, Cisco NX-OS applies the running configuration.

Virtualization Support for RMON

Cisco NX-OS supports one instance of RMON.

RMON is virtual routing and forwarding (VRF) aware. You can configure RMON to use a particular VRF to reach the RMON SMTP server.

Guidelines and Limitations for RMON

RMON has the following configuration guidelines and limitations:

  • You must configure an SNMP user and a notification receiver to use the SNMP notification event type.

  • You can configure an RMON alarm only on a MIB object that resolves to an integer.

  • When you configure an RMON alarm, the object identifier must be complete with its index so that it refers to only one object. For example, 1.3.6.1.2.1.2.2.1.14 corresponds to cpmCPUTotal5minRev, and .1 corresponds to index cpmCPUTotalIndex, which creates object identifier 1.3.6.1.2.1.2.2.1.14.1.

Default Settings for RMON

The following table lists the default settings for RMON parameters.

Parameters

Default

RMON

Enabled

Alarms

None configured

Events

Configured (but triggered event causes nothing)

Configuring RMON


Note
Be aware that the Cisco NX-OS commands for this feature may differ from those commands used in Cisco IOS.

Configuring RMON Alarms

You can configure RMON alarms on any integer-based SNMP MIB object.

You can optionally specify the following parameters:

  • The event number to trigger if the rising or falling threshold exceeds the specified limit.

  • The owner of the alarm.

Ensure you have configured an SNMP user and enabled SNMP notifications.

Before you begin

Make sure that you have configured an SNMP user and enabled SNMP notifications.

SUMMARY STEPS

  1. configure terminal
  2. rmon alarm index mib-object sample-interval {absolute | delta} rising-threshold value [event-index] falling-threshold value [event-index] [owner name]
  3. rmon hcalarm index mib-object sample-interval {absolute | delta} rising-threshold-high value rising-threshold-low value [event-index] falling-threshold-high value falling-threshold-low value [event-index] [owner name] [storagetype type]
  4. (Optional) show rmon {alarms | hcalarms}
  5. (Optional) copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:

switch# configure terminal
switch(config)#

Enters global configuration mode.

Step 2

rmon alarm index mib-object sample-interval {absolute | delta} rising-threshold value [event-index] falling-threshold value [event-index] [owner name]

Example:

switch(config)# rmon alarm 20 1.3.6.1.2.1.2.2.1.14.1 2900 
delta rising-threshold 1500 1 falling-threshold 0 owner test

Creates an RMON alarm. The value range is from –2147483647 to 2147483647. The owner name can be any alphanumeric string.

Step 3

rmon hcalarm index mib-object sample-interval {absolute | delta} rising-threshold-high value rising-threshold-low value [event-index] falling-threshold-high value falling-threshold-low value [event-index] [owner name] [storagetype type]

Example:

switch(config)# rmon alarm 20 1.3.6.1.2.1.2.2.1.14.16777216 2900 
delta rising-threshold-high 15 rising-threshold-low 151 
falling-threshold-high 0 falling-threshold-low 0 owner test

Creates an RMON high-capacity alarm. The value range is from –2147483647 to 2147483647. The owner name can be any alphanumeric string.

The storage type range is from 1 to 5.

Step 4

(Optional) show rmon {alarms | hcalarms}

Example:

switch(config)# show rmon alarms
 (Optional)

Displays information about RMON alarms or high-capacity alarms.

Step 5

(Optional) copy running-config startup-config

Example:

switch(config)# copy running-config startup-config
(Optional)

Copies the running configuration to the startup configuration.

Configuring RMON Events

You can configure RMON events to associate with RMON alarms. You can reuse the same event with multiple RMON alarms.

Before you begin

Make sure you have configured an SNMP user and enabled SNMP notifications.

SUMMARY STEPS

  1. configure terminal
  2. rmon event index [description string] [log] [trap string] [owner name]
  3. (Optional) show rmon events
  4. (Optional) copy running-config startup-config

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:

switch# configure terminal
switch(config)#

Enters global configuration mode.

Step 2

rmon event index [description string] [log] [trap string] [owner name]

Example:

switch(config)# rmon event 1 trap trap1

Configures an RMON event. The description string, trap string, and owner name can be any alphanumeric string.

Step 3

(Optional) show rmon events

Example:

switch(config)# show rmon events
 (Optional)

Displays information about RMON events.

Step 4

(Optional) copy running-config startup-config

Example:

switch(config)# copy running-config startup-config
(Optional)

Copies the running configuration to the startup configuration.

Verifying the RMON Configuration

To display RMON configuration information, perform one of the following tasks:

Command

Purpose

show rmon alarms

Displays information about RMON alarms.

show rmon events

Displays information about RMON events.

show rmon hcalarms

Displays information about RMON high-capacity alarms.

show rmon logs

Displays information about RMON logs.

Configuration Examples for RMON

This example shows how to create a delta rising alarm on ifInOctets.14 and associates a notification event with this alarm: 

configure terminal
rmon alarm 20 1.3.6.1.2.1.2.2.1.14.1 2900 delta rising-threshold 1500 1 falling-threshold 0 owner test
rmon event 1 trap trap1