When you configure Network Address Translation (NAT), the virtual machine shares the IP address and MAC address of the host system.

The virtual machine and the host system share the a single identity that is not visible outside the network. The virtual machine does not have its own IP address. Instead, a separate private network is set up on the host system and the virtual machine obtains an address on that network from the VMware virtual DHCP server. The VMware NAT device passes network data between one or more virtual machines and the external network. The VMware NAT device identifies incoming data packets that are intended for each virtual machine and sends them to the correct destination.

With NAT, a virtual machine can use many standard protocols to connect to other machines on the external network. For example, you can use HTTP to browse Web sites, FTP to transfer files, and Telnet to log in to other systems. You can also connect to a TCP/IP network by using a Token Ring adapter on the host system.

In the default configuration, systems on the external network cannot initiate connections to the virtual machine. For example, the default configuration does not let you use the virtual machine as a Web server to send Web pages to systems on the external network. This limitation protects the guest operating system from being compromised before you can install security software.

By default, NAT is used when you use the New Virtual Machine wizard to create a virtual machine.

The virtual machine uses NAT to connect to the Internet or other TCP/IP network by using the networking connection on the host system. NAT works with Ethernet, DSL, and phone modems. A separate private network is set up on the host system. The virtual machine obtains an address on that network from the VMware virtual DHCP server.