`VMnet8` is the default virtual network switch for the `NAT` network type in VMware Workstation

«Using VMware Workstation Pro» → «Configuring Network Connections» → «Understanding Virtual Networking Components»:

docs.vmware.com/en/VMware-Workstation-Pro/14.0/com.vmware.ws.using.doc/GUID-8FDE7881-C31F-487F-BEF3-B2107A21D0CE.html#GUID-8FDE7881-C31F-487F-BEF3-B2107A21D0CE__GUID-F3A673AF-D3B5-409D-83F6-14C772F86375

See also: