Configuring NAT on Linux Hosts

Configuring NAT on Linux Hosts
Unfortunately, VMware Server on Linux currently lacks a user friendly equivalent of the Windows Manage Virtual Networks tool, instead requiring the manual editing of the /etc/vmware/vmnet8/nat/nat.conf file (keeping in mind that the vmnet8 name will need to be changed if the settings are to be configured for a custom created virtual network).
The nat.conf file contains a number of different sections, each allowing a different aspect of the NAT device to be configured:

[host]

• ip - The IP address of the NAT device on the virtual network. By default this will be .2 where the is the subnet address assigned to the virtual network (for example, 172.16.86.2).

• netmask - The subnet mask to be used for the NAT device.

• configport - The port to be used for accessing information about the NAT device. By default this directive is commented out with a # character for security purposes and is supposedly only for use by VMware Inc's technical support staff.

• device - The VMnet virtual network switch to which the NAT device is attached.

• activeFTP - A value of 1 indicates that active FTP sessions (i.e connections initiated by remote FTP servers) are supported. A setting of 0 limits connections to passive sessions.

[udp]

• timeout - The amount of time, in seconds, to keep UDP mapping for the NAT device. This is essentially the amount of time for which the NAT device remembers which virtual machine initiated a specific UDP based connection with an external system. If the external system responds after the timeout period has elapsed, the NAT will no longer know to which virtual machine the data should be forwarded, and the UDP packet will be discarded.

[incomingtcp]

The [incomingtcp] section of the nat.conf file is used to configure TCP port forwarding. This essentially involves mapping an incoming TCP port on the host to the IP address and TCP port of a virtual machine. For example, to map data coming into TCP port 8080 on the host to port 80 on a virtual machine with an IP address of 172.16.86.128, the following directive would need to be entered into the [incomingtcp] section of the configuration file:

8080 = 172.16.86.128:80

As many TCP port forwarding directives as necessary may added to this section of the NAT configuration file.

[incomingudp]

The [incomingudp] section of the nat.conf file is used to configure UDP port forwarding. Similar to the [incomingtcp]] section, this essentially involves mapping an incoming UDP port on the host to the IP address and UDP port of a virtual machine. For example, to map data coming into UDP port 8081 on the host to port 8082 on a virtual machine with an IP address of 172.16.86.128, the following directive would need to be entered into the [incomingudp] section of the configuration file:

8081 = 172.16.86.128:8082

As many port UDP forwarding directives as necessary may added to this section of the NAT configuration file.