Removing a Network Extension

Removing a network extension prevents further cross-site communications between virtual machines residing on that network. This operation is typical when the source side network is vacated.

You can remove a network extension at any time, but be aware that removing an extended network can impact the network infrastructure. Migrated virtual machines that use a source environment DHCP server or that use statically assigned network services like DNS or NTP can lose those services after unextending a network.

Procedure

1. In the HCX Manager UI, select Services > Network Extension.

   The system displays a list of extended networks.

2. Select the network or networks that must be unextended, and click the ellipsis menu to see a list of actions.
3. Select Unextend Network.

   The interface opens and displays the selected network.

   Note:

   To remove multiple network extensions simultaneously, select the networks and click the Unextend Networks tab.

   If Unextend Networks fails due to the state of the Network Extension appliance, use Force Unextend to remove the extension and clear internal operations and processes from the source and the destination sites. In HCX protection operations where the source components are no longer available, Force Unextend allows the Unextend operation, removing Network Extension components from the source and the destination sites.

4. (Optional) Expand the network entry and select Connect cloud network to cloud edge gateway after unextending to connect the remote side gateway.

   Dynamic routing can be activated on the Cloud Edge Gateway as part of the OSPF or the BGP configuration. By default, the cloud segment is left disconnected from the Edge Gateway after removing the network extension. This is done to prevent an Edge Gateway from advertising a route to the cloud segment and causing a potential routing conflict with the network in the on-premises data center. Selecting this option connects the segment to the Cloud Edge Gateway after removing the network extension. If dynamic routing is activated, the network is advertised from the Cloud Edge Gateway. Refer to VMware Cloud on AWS Networking and Security guide to ensure proper routing configuration.

   Note:

   Unextending a network removes the HCX L2 bridged path without removing the NSX Segment or vSphere Port Group, or NSX interface. The NSX router interface remains disconnected when the option Connect cloud network is not used.

5. To confirm the operation, click Unextend.

Results

HCX removes the network extension.