The NAT configuration file is divided into sections. The parameters in each section configure a part of the NAT device.

The [host] section includes parameters to configure the NAT connection.

[host] Section Parameters

Parameter

Description

ip

The IP address that the NAT device should use. It can be followed by a slash and the number of bits in the subnet.

netmask

The subnet mask to use for the NAT network. DHCP addresses are allocated from this range of addresses.

configport

A port that can be used to access status information about the NAT device.

device

The VMnet device to use. Windows devices are of the form vmnetx where x is the number of the VMnet. Linux devices are of the form /dev/vmnetx.

activeFTP

Flag to indicate if active FTP is to be allowed. Active FTP allows incoming connections to be opened by the remote FTP server. Turning this off means that only passive mode FTP works. Set this flag to 0 to turn it off.

The [udp] section contains the timeout parameter, which specifies the number of seconds to keep the UDP mapping for the NAT network.

The [dns] section is for Windows hosts only. Linux hosts do not use this section.

[dns] Section Parameters

Parameter

Description

policy

Policy to use for DNS forwarding.

order sends one DNS request at a time in the order of the name servers.

rotate sends one DNS request at a time and rotate through the DNS servers.

burst sends to three servers and wait for the first one to respond.

timeout

Time in seconds before retrying a DNS request.

retries

Number of retries before the NAT device stops trying to respond to a DNS request.

autodetect

Flag to indicate whether the NAT device should detect the DNS servers available to the host.

nameserver1

IP address of a DNS server to use.

nameserver2

IP address of a DNS server to use.

nameserver3

IP address of a DNS server to use.

If autodetect is on and some name servers are specified, the DNS servers specified in nameserver1, nameserver2, and nameserver3 are added before the list of detected DNS servers.

The [netbios] section applies to Windows hosts only. Linux hosts do not use this section.

[netbios] Section Parameters

Parameter

Description

nbnsTimeout = 2

Timeout, in seconds, for NBNS queries.

nbnsRetries = 3

Number of retries for each NBNS query.

nbdsTimeout = 3

Timeout, in seconds, for NBDS queries.

The [incomingtcp] section configures TCP port forwarding for NAT. You can assign a port number to an IP address and port number on a virtual machine.

This example creates a map from port 8887 on the host to the IP address 192.168.27.128 and port 21.

8887 = 192.168.27.128:21

When this map is set and an external machine connects to the host at port 8887, the network packets are forwarded to port 21 (the standard port for FTP) on the virtual machine that has IP address 192.168.27.128.

The [incomingudp] section configures UDP port forwarding for NAT. You can assign a port number to an IP address and port number on a virtual machine.

This example creates a map from port 6000 on the host to the IP address 192.168.27.128 and port 6001.

6000 = 192.168.27.128:6001

When this map is set and an external machine connects to the host at port 6000, the network packets are forwarded to port 6001 on the virtual machine that has IP address 192.168.27.128.