"A specified parameter was not correct: macManagementPolicy" when trying to re-extend a HCX network.

Products

• VMware HCX

Issue/Introduction

• After a manual change from the vCenter UI on the HCX extended network (DVS portgroup) and/or the NE VMs' network, a network outage happened.
• Trying to unextend the network failed, and using the force unextension, the network was successfully unextended.
• Post force unextension of the network, you are unable to extend it again, with the following error observed from HCX Manager -> Activity logs:
  Error: VC task task-###### failed on VC https://<FQDN/IP>
  
  
  
• From the vCenter UI -> Tasks:
  A specified parameter was not correct: macManagementPolicy
  
• The following error is also observed from HCX Manager /common/logs/admin/app.log

  <timestamps> UTC [NetworkStretchService_SvcThread-253, j: #########, , TxId: #########-####-####-####-#########] WARN  c.v.v.h.n.i.AbstractJobInt- Exception in NetworkStretchJobs:ApplianceConfigCallbackJob. Reason : VC task task-### failed on VC https://<vCenter FQDN/IP>
  <timestamps> UTC [NetworkStretchService_SvcThread-253, j: #########, , TxId: #########-####-####-####-#########] WARN  c.v.v.h.n.i.AbstractJobInt- ApplianceConfigCallbackJob failed in state WAIT_FOR_VC_TASKS. Error: VC task task-### failed on VC https://<vCenter FQDN/IP>. Retry attempt: 0
  java.lang.RuntimeException: VC task task-### failed on VC https://<vCenter FQDN/IP>
  Caused by: com.vmware.vim.binding.vmodl.fault.InvalidArgument: A specified parameter was not correct: macManagementPolicy
          at jdk.internal.reflect.GeneratedConstructorAccessor130.newInstance(Unknown Source)
          at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

Environment

VMware HCX

Cause

Manual changes/reconfiguration directly from vCenter on portgroups being extended by HCX are not supported.

Resolution

Before extending the network again using the workaround provided below, click on the original NE VM -> "Edit settings" and ensure the portgroup is not connected to the network.
Please do not manually remove the network adapter and only disconnect the affected extended network from the NE VM  (by unselecting the 'Connected' option).
This action needs to be done only for the network which you are trying to extend again.

E.g:

Workaround:

1. Create a new Service Mesh, and only select the "Network Extension" option (other services are not required).
2. From Network Extension tab, click "+Extend networks" and from "Select Service Mesh" select the new service mesh you created, and then select the network you are trying to extend again.
3. Provide the details for the Mandatory Fields (gateway, extension appliance, destination first-hop router), and click Submit.

Additional Information

Removing a Network Extension