The ability to connect to a virtual machine using a VNC client has been available since the early days of VMware GSX as described by this VMware KB article. The required .vmx configuration can also be applied to virtual machines running on ESX(i), but is not officially supported by VMware. With ESXi 5, this continues to work but there is one additional caveat users should to be aware of, which is the new firewall that has been introduced in ESXi 5.

In addition to the three .vmx configurations:

RemoteDisplay.vnc.enabled = [true|false]

RemoteDisplay.vnc.port = [port #]

RemoteDisplay.vnc.password = [optional]

Users need to also enable the ports selected for each virtual machine on the ESXi firewall. Here is an example of a firewall rule that needs to be created:

Take a look at this blog post for details on configuring custom firewall rules including persisting the custom rules upon a system reboot.

Here are a few screenshots of configuring the .vmx configurations and using a VNC client to connect to the powered on virtual machine.

Only the first two .vmx configurations are required, if you do not set a password, anyone can connect to the virtual machine as long as they know the hostname/IP Address of your ESX(i) host and port.

To connect to a specific virtual machine, you will specify the hostname/IP Address of the ESX(i) host and port for the given virtual machine. If you set a password, you will need to also provide that before you can connect.

Please be aware of the limitations and security concerns of using VNC. VMware Remote Console or standard RDP/SSH should still be considered for virtual machine remote access.