Network Address Translation (NAT)

Protoport Personal Firewall features a NAT server. NAT server allows several home networks to connect to the internet via one computer connected to both provate networks, and Internet.

NAT acts as an interpreter between two networks. In the case of a home network, it sits between the internet and your home network. The internet is considered the public side and your home network is considered the private side. When a computer in the private side request data from the public side (the internet), the NAT device will open a little conduit between your computer and the destination computer. When the public computer returns results from the request, it is passed back through the NAT device to the requesting computer.

In addition to network address translation, Protoport firewall will translate port numbers as well.

This technology is sometimes called Network Address Port Translation or NAPT and refers to network address translation involving the mapping of port numbers, allowing multiple machines to share a single IP address.

NAT Configuration

• Enable Network Address Translation - put a checkmack there if you are gogin to use NAT. Otherwise, remove checkmark in order to release any NAT-specific system resources.
• NAT1, NAT2, NAT3 - Protoport firewall supports up to three NAT servers. In other words, it can connect up to three home networks to the internet. Select which NAT server you want to configure.
• Enable NAT server - enable the checkbox it you want to use selected NAT server.
• Eable Rules - if enabled, Protoport firewall will check all NAT packets against the rules. You can specify to allow certain packets or block them. NAT werver may be setup to limit internet bandwidth for certain computers within home network. Note: overall network performance will be slightly decreased if this option is enabled.
• Interface, connected to the external network - select a network card that is connected to the Internet.
• Interface, connected to the private network - select a network card that is connected to the home network.
• First and Last port numbers - specify a port number range that NAT server can use when mapping ports.