You can use the migration coordinator to migrate an existing vSphere Distributed Switch configuration to an NSX-T Data Center environment.

For vSphere Distributed Switch versions 6.5.0 and 6.6.0, Migration coordinator moves the vSphere Distributed Switch, compute hosts, PNICs, vmkNICs, and vNIC backings to the N-VDS.

Note: For vSphere Distributed Switch version 7.0, vSphere networking to NSX-T Data Center migration is not supported. It is recommended you perform a fresh install of NSX-T Data Center and configure it for use with your vSphere deployment.
Note: You can use migration coordinator to migrate vSphere Distributed Switch configurations to NSX-T only if NSX for vSphere is not installed on the host.