Activate Network Extension High Availability to provide failover protection for extended networks.

Network Extension High Availability activation is initiated only from the source site.


  • In the HCX Compute Profile, the Network Extension Appliance Limit is set to allow for the number of Network Extension appliances. See Creating a Compute Profile.

  • In the HCX Service Mesh, the Network Extension Appliance Scale Out Appliance Count is set to provide enough appliances to support network extension objectives, including any Network Extension HA groups. See Creating a Service Mesh.

  • The Network Extension appliances selected for HA activation must have no networks extended over them.
  • Only Network Extension appliances upgraded to HCX 4.3.0 or later can be added to HA Groups.
  • In environments with vCenter in Linked Mode, all HCX systems have HCX 4.3.0 or later for HA objects to display correctly.


  1. At the source site, navigate to Interconnect > Service Mesh > Appliances.
  2. Select an available Network Extension appliance and click Activate High Availability.

    A pop-up window appears to confirming activation.

    If the Network Extension appliance is already extending a network, or not enough appliances are available to create an HA group, the pop-up window provides information about the issue.

  3. Click Activate HA.

    The HCX system starts the process of creating the HA group. The HCX Manager automatically selects the second pair of Network Extension appliances to form the HA group. To view the activation progress, select the Tasks tab.

  4. Review the list of appliances to verify the Active and Standby assignments.

    The appliance information shows both the HA group role and the partner appliance in the group.

  5. To view detailed state and role information about HA groups, click the HA Management tab.


After the group is created, the Active and Standby roles for the local and remote appliances display on the HA Management page.

What to do next

Select a Network Extension HA group when extending networks. See Extending Networks Using VMware HCX.