Which three features are only available when using vSphere Distributed Switches instead of vSphere Standard...

Three features that are only available when using vSphere Distributed Switches instead of vSphere Standard Switches are port mirroring, which allows monitoring network traffic on a virtual switch port; Netflow, which allows collecting IP traffic information from a virtual switch; and configuration backup and restore, which allows saving and restoring distributed switch settings.

References: https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.networking.doc/GUID-D5960C77-0D19-4669-A00C-B05D58A422F8.html https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.networking.doc/GUID-A59628EA-9854-4551-B310-B843C78E087A.html https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.networking.doc/GUID-E9EB9D18-692A-4485-A3D1-BF6BF6574AD2.html