Failed to install NSX on Host in vLCM enabled cluster with error "Failed to send HostConfig RPC to MPA"

Products

• VMware NSX

Issue/Introduction

vLCM configured ESXi hosts fail to install NSX with "Install Failed" status in NSX UI and below errors:

• "Host configuration: Failed to send the HostConfig message.
  

   [TN=TransportNode/<uuid>]. Reason: Failed to send HostConfig RPC to MPA TN:<uuid>. Error: Unable to reach client <tn-uuid>, application SwitchingVertical."

Environment

VMware NSX

Cause

The "Waiting for connection to Managers" stage of the installation process exceeded the default timeout threshold of 5 minutes while attempting to establish a connection with the NSX Managers.

Resolution

 

Resolution / Workaround:

To successfully uninstall and reinstall NSX on an affected ESXi host within a vLCM-enabled environment, follow the steps below:

1. Place the Host in Maintenance Mode (MM):
   Migrate all workloads off the affected host and place it into maintenance mode.

2. Remove NSX from Host via UI:

   • Navigate to System > Fabric > Hosts > Standalone/Other Nodes.

   • Select the affected host and click Delete NSX.

   • If the host status changes to Orphaned, reselect the host and click Delete NSX > Force Delete NSX.

3. Verify Host Status:
   Confirm the host now shows as Not Configured in the NSX Manager UI.

4. Confirm VIB Removal via CLI:
   SSH into the host and run the following to check for remaining NSX VIBs:

   esxcli software vib list | grep nsx
   

5. Manually Remove VIBs if Still Present:

   • Stop the nsx-proxy service:

     /etc/init.d/nsx-proxy stop
     

   • Remove NSX components:

     nsxcli -c del nsx
     

6. Verify VIBs are Fully Removed:
   Run the esxcli command again to confirm all NSX VIBs have been removed:

   esxcli software vib list | grep nsx
   

7. Reboot (for vLCM-managed Hosts):
   If the host is managed by vLCM, a reboot is required after the VIBs are removed using the nsxcli -c del nsx method above. Wait for the VIBs to be cleared before initiating the reboot.

8. Migrate Host into Cluster:
   After reboot and confirmation that VIBs are removed, migrate the host back into the vLCM-enabled NSX cluster. NSX installation should reinitiate automatically.

9. Post-Validation:
   Once installation completes successfully:

   • Exit Maintenance Mode.

   • Migrate a few VMs to the host and verify that Geneve tunnels and other services come up as expected.

Reference:
Uninstall NSX from a Managed Host in a vSphere Cluster