"Failed to send HostConfig RPC to MPA" error on Host Transport Nodes in Install Failed state.

Products

• VMware NSX

Issue/Introduction

• ESXi hosts are in "Failed/Host Disconnected" status with below error:

  "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."

• Using the Resolve action to reconfigure NSX for the TN keeps failing with the same error
• On the affected ESXi host(s), the commands:
  nsxcli -c get managers
nsxcli -c get controllers
  report no disconnection or connectivity problems with the NSX managers and controllers.
• On the affected ESXi TN(s), the logfile at /var/run/log/nsx-syslog.log indicates timeouts to the localhost address 127.0.0.1.
• vMotion operations for VMs connected to NSX segments consistently fail.

Environment

VMware NSX

Cause

While the transport node is connecting correctly to NSX CCP there is an internal failure to forward the configuration commands because nsx-proxy cannot communicate with another internal service such as nsx-opsagent

Resolution

Restart the nsx-opsagent and nsx-proxy services from CLI on the affected ESXi TN(s):

/etc/init.d/nsx-opsagent restart
/etc/init.d/nsx-proxy restart