How do I verify that health or performance monitoring will work via SNMP on my monitored device?

Article ID: 380
Category: Heartbeat Monitoring
Applies to: All
Updated: 2018-11-07

Your device must support SNMP-get, sometimes referred to as SNMP polling, and must be able to accept incoming connections on UDP port 161. If your device has its own firewall settings (Linux, Mac, ESXi, certain network devices) you'll need to unblock SNMP and/or unblock UDP 161 inbound in your device's firewall settings in addition to allowing any local or network firewall rules to permit the EventSentry server to send traffic to your monitored devices on UDP port 161.

If you have configured your device's SNMP community settings (for SNMP v1, v2, v2c) or SNMP user and password settings (for SNMP v3) you will need to configure the [SNMP authentication settings] in EventSentry for your device, and then save your new settings in EventSentry.

Select your host/device in EventSentry and then use the toolbar buttons to click Check Status and then click Go. If you do not receive an error message and the SNMP column of the results shows a version (v1, v2, v2c, v3) the SNMP health or performance monitoring will be successful for the selected device.

If you receive the error "access denied" this means you have not configured the correct SNMP authentication for this device, or that the configured SNMP user or community does not have the necessary Read permissions to monitor your device. Please ensure that the user or community has generic Read permissions for SNMP, and if the device supports specific OID permissions please grant Read access to the necessary OID trees (such as .1 or . or grant Read permissions for the specific OID values you need to monitor, such as

If you receive an "SNMP v3 Authentication Error" please see [knowledge base article 379].

If you do not receive an error, but the SNMP column says NO, please ensure that any SNMP services or daemons are currently running on your device. Also please ensure that your EventSentry server is able to reach your device on UDP port 161. You can verify that the EventSentry server can reach UDP port 161 on your device using the following steps:

  • Download and install Microsoft PortQryUI:
  • Go to the folder where you installed Microsoft PortQryUI, and run portqueryui.exe
  • Specify your device's IP in the destination IP field. Select "Manually input query ports" and specify port 161 as the port to query, and choose UDP in the protocol drop-down. Then click the Query button at the bottom to test the connection.
  • If the result says "LISTENING OR FILTERED" that means the device is correctly allowing UDP port 161. Any other result means that the port is blocked, or that there is a routing problem.