Configure Remote Network Monitoring (RMON) Alarms on a Switch

Objective

Remote Network Monitoring (RMON) was developed by the Internet Engineering Task Force (IETF) to support monitoring and protocol analysis of Local Area Networks (LANs). It is a standard monitoring specification which enables different network monitors and console systems to exchange their network-monitoring data with each other. RMON facilitates network administrators to choose among the network-monitoring probes and consoles with features that meet their particular networking needs. RMON specifically defines the information that any network monitoring system should be able to provide. Statistics, events, history, alarms, hosts, hosts top N, matrix, filter, capture, and token ring are the ten groups in RMON.

RMON alarms provide a mechanism for setting thresholds and sampling intervals to generate exception events on counters or any other Simple Network Management Protocol (SNMP) object counter maintained by the agent. Both the rising and falling thresholds must be configured in the alarm. After a rising threshold is crossed, no rising events are generated until the companion falling threshold is crossed. After a falling alarm is issued, the next alarm is issued when a rising threshold is crossed.

Note: To know how to configure SNMP settings on your switch, click here for instructions.

One or more alarms are bound to an event, which indicates the action to be taken when the alarm occurs. Before you configure the RMON alarms on your switch, make sure the RMON event control settings have been configured. To learn how, click here.

This article provides instructions on how to configure RMON alarms on your switch.

Applicable Devices

• Sx250 Series
• Sx300 Series
• Sx350 Series
• SG350X Series
• Sx500 Series
• Sx550X Series

Software Version

• 1.4.7.05 — Sx300, Sx500
• 2.2.8.04 — Sx250, Sx350, SG350X, Sx550X

Configure RMON Alarms on your Switch

Step 1. Log in to the web-based utility of your switch then choose Advanced in the Display Mode drop-down list.

Note: In this example, SG350X-48MP switch is used.

Note: If you have an Sx300 or Sx500 Series switch, skip to Step 2.

Step 2. Choose Status and Statistics > RMON > Alarms.

Step 3. Click Add to add a new entry to the Alarm Table.

The Alarm Entry area displays the alarm entry number.

Step 4. Choose the type of interface for which RMON statistics are displayed.

Note: In this example, Port GE2 of Unit 1 is chosen.

Note: If you have a non-stackable switch such as Sx250 or Sx300 Series switch, the options are Port and LAG only.

Step 5. Choose the counter name from the Counter Name drop-down list. The Counter Name has a list of Management Information Base (MIB) variables that indicate the type of occurrence measured.

Note: In this example, Multicast Packets – Receive 1 is chosen.

Step 6. Choose the sampling method to generate an alarm. The options are:

• Absolute — If the threshold is crossed, an alarm is generated.
• Delta — Subtracts the last sampled value from the current value. The difference in the values is compared to the threshold. If the threshold was crossed, an alarm is generated.

Note: In this example, Absolute is chosen.

Step 7. Enter the rising threshold value in the Rising Threshold field. This is the value which is used to set off the rising threshold alarm.

Note: In this example, 150 is used.

Step 8. Choose an event to be carried out from the Rising Event drop-down list. This event starts when the rising event is triggered.

Note: In this example, 1 – Log and Trap is chosen.

Step 9. Enter the falling threshold value in the Falling Threshold field. This is the value which is used to set off the falling threshold alarm.

Note: In this example, 25 is used.

Step 10. Choose an event to be carried out from the Falling Event drop-down list. This event starts when the falling event is triggered.

Note: In this example, 2 – Trap is used.

Step 11. Click the desired alarm which you want to be active at startup in the Startup Alarm area. Once this is crossed, all other alarms apply as normal.

The options are:

• Rising Alarm — This alarm is triggered by the rising value.
• Falling Alarm — This alarm is triggered by the falling value.
• Rising and Falling — This alarm is triggered by rising and falling values.

Note: When the threshold is crossed from a lower value to a higher value then it is called rising.

Note: In this example, Rising and Falling is chosen.

Step 12. In the Interval field, enter the alarm interval time in seconds.

Note: In this example, 120 seconds is used.

Step 13. Enter the name of the user or network management system that receives the alarm in the Owner field.

Note: In this example, cisco is used.

Step 14. Click Apply then click Close. The RMON alarm is saved to the running configuration file.

Step 15. (Optional) Click Save to save settings to the startup configuration file.

You should now have successfully added a new entry in the Alarm Table.

Edit RMON Alarms

Step 1. In the Alarm Table, check the box next to the Alarm Entry that you would like to edit.

Step 2. Click the Edit button to edit the RMON alarm entry.

Step 3. (Optional) Edit the alarm details accordingly.

Note: In this example, the Falling Threshold value has been changed from 25 to 30.

Step 4. Click Apply then click Close.

Step 5. (Optional) Click Save to save settings to the startup configuration file.

You should now have successfully edited the alarm in the Alarm Table.

Delete RMON Alarms

Step 1. In the Alarm Table, check the box next to the Alarm Entry that you would like to delete.

Step 2. Click the Delete button to edit the RMON alarm entry.

Step 3. (Optional) Click Save to save settings to the startup configuration file.

You should now have successfully deleted an alarm from the Alarm Table.

Revision History

Revision	Publish Date	Comments
1.0	13-Dec-2018	Initial Release