Applications Systems

VMAN: polling ESXi nodes via port 5989

First published date

9/28/2026 5:38 PM

Last published date

9/28/2026 5:38 PM

Overview

You are polling an ESXi server and can retrieve VM information. However, SolarWinds is attempting to communicate over TCP port 5989, which is currently blocked by your firewall.

 

Product section

Virtualization Manager

Resolution

TCP port 5989 is not required for basic VM performance and inventory monitoring when the ESXi host is already being monitored successfully.

Port 5989 is specifically used for CIM-based hardware health monitoring of the physical ESXi host. When TCP 5989 is allowed between the SolarWinds polling engine and the ESXi host, SolarWinds can collect physical hardware health information, including:

  • Chassis health
  • Fan status
  • Temperature sensors
  • Power supply status
  • Physical hardware status
  • Related hardware alerts

The connection is read-only and is established directly between the SolarWinds polling engine and the ESXi host.

Therefore, TCP port 5989 should only be allowed when direct physical hardware-health monitoring of the ESXi host is required, particularly when the ESXi host is being polled directly rather than through vCenter.

In the SolarWinds Platform, navigate to Settings > Virtualization Settings > VMware Settings and verify the configured VMware polling method.

If the ESXi host is monitored through vCenter and direct physical hardware-health monitoring is not required, TCP port 5989 can remain blocked.

If direct hardware-health monitoring is required, allow TCP port 5989 for communication from the SolarWinds polling engine to the ESXi host.

Disabling CIM-Based Hardware Monitoring

The Disable Polling option disables VMAN polling for the selected ESXi node entirely; it does not only disable CIM communication over port 5989.

To stop CIM-based hardware sensor requests while continuing normal VMAN monitoring:

  1. Navigate to Settings > All Settings > Manage Hardware Sensors.
  2. Select the hardware-health sensors associated with the affected ESXi host.
  3. Click Disable.

Once disabled, the selected hardware sensors will no longer be collected, and the change will take effect during the next polling cycle.