VMware GSX Server 3.2

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Custom NAT and DHCP Configuration on a Windows Host

If you are an advanced user on a Windows host computer, you may wish to make custom configuration settings by editing the NAT and DHCP configuration files. If your host operating system is installed on the C drive, the configuration files for NAT and DHCP are in the following locations:

Note: You can change many key NAT and DCHP settings using the Virtual Network Editor (Host > Virtual Network Settings). However, if you have made manual changes to the configuration files, some or all of those changes may be lost when you use the Virtual Network Editor. If you have made manual changes, you should make backup copies of the files before changing any settings in the Virtual Network Editor. After making changes in the Virtual Network Editor, you can copy your manual changes back into the appropriate configuration files.

Specifying Connections from Ports Below 1024

When a client machine makes a TCP or UDP connection to a server, the connection comes from a particular port on the client (the source port) and connects to a particular port on the server (the destination port). For security reasons, some servers accept connections only from source ports below 1024.

If a virtual machine using NAT attempts to connect to a server that requires the client to use a source port below 1024, it is important that the NAT device forward the request from a port below 1024. You can specify this behavior in the vmnetnat.conf file.

This behavior is controlled by entries in sections headed [privilegedUDP] and [privilegedTCP]. You may need to add settings to or modify settings in either or both of these sections, depending on the kind of connection you need to make.

You can set two parameters, each of which appears on a separate line.

autodetect = <n>
The autodetect setting determines whether the VMware NAT device automatically attempts to map virtual machine source ports below 1024 to NAT source ports below 1024. A setting of 1 means true. A setting of 0 means false. On a Windows host, the default is 1 (true). On a Linux host, the default is 0 (false).

port = <n>
The port setting specifies a destination port (<n> is the port on the server that accepts the connection from the client). Whenever a virtual machine connects to the specified port on any server, the NAT device attempts to make the connection from a source port below 1024. You may include one or more port settings in the [privilegedUDP] or [privilegedTCP] section or in both sections, as required for the connections you need to make. Each port setting must be entered on a separate line.