With L2 VPN, you can configure a tunnel between vCloud Director and an on-premise vCenter Server. Because CX Connector installs a VPN client on on-premise side you must have NSX Edge installed and configured at the cloud provider side.
To create the L2 VPN tunnel, you configure an L2 VPN Server and L2 VPN Client.
For more information, see L2 VPN Overview in NSX Administration Guide.
For more information on L2 VPN configuration and troubleshooting, see L2 VPN in NSX Troubleshooting Guide.