When you install Workstation on a Windows or Linux host system, a NAT network (VMnet8) is set up for you. When you use the New Virtual Machine wizard to create a typical virtual machine, the wizard configures the virtual machine to use the default NAT network.

With NAT, a virtual machine does not have its own IP address on the external network. Instead, a separate private network is set up on the host system. In the default configuration, virtual machines get an address on this private network from the virtual DHCP server.

NAT Configuration
Network connection between a virtual machine and host computer using a NAT device.

The virtual machine and the host system share a single network identity that is not visible on the external network. NAT works by translating the IP addresses of virtual machines in the private network to the IP address of the host system. When a virtual machine sends a request to access a network resource, it appears to the network resource as if the request is coming from the host system.

The host system has a virtual network adapter on the NAT network. This adapter enables the host system and virtual machines to communicate with each other. The NAT device passes network data between one or more virtual machines and the external network, identifies incoming data packets intended for each virtual machine, and sends them to the correct destination.

NAT is useful when the number of IP addresses is limited or the host system is connected to the network through a non-Ethernet adapter.

You can use the virtual network editor to change NAT settings. For example, you can change the gateway IP address, add a port for forwarding, and change DNS and NetBIOS settings.

If you are an advanced user, you can edit the NAT configuration file to modify NAT settings.

If you use NAT networking in a Windows virtual machine running on a Windows host system, you can use NetLogon to log in to a Windows domain from the virtual machine and access file shares that the WINS server knows.

If a virtual machine that uses NAT attempts to connect to a server that requires the client to use a source port below 1024, the NAT device must forward the request from a port below 1024. For security reasons, some servers accept connections only from source ports below 1024.