What is a NAT?
Presently there are over 100 million servers and 350 million users on the Internet. In order for successful and efficient communication, each computer and server needs an IP (Internet Protocol) address. An IP address is a unique 32-bit number (IPv4) that identifies the location of a specific computer on the network. Mathematically, there can be up to 4,294,967,296 unique addresses (2^32), but in reality there are only 3.2 to 3.3 billion due to class separation, multicasting, testing, and other use. The size of the Internet is increasing exponentially and the rate of growth will soon exhaust the depleting resource. To delay the inevitable conversion to an IPv6 infrastructure to allow for more possible addresses, Cisco introduced the Network Address Translator (RFC 1631). A NAT gateway sits on the border between private and public networks, converting private addresses defined by RFC 1918 into legally registered public IP addresses allocated by IANA. This means that an entire group of ho
If you use the consumer version of a DirecWay product, the IP address of your satellite adapter is not routable on the internet. It can only be used on private networks. Hughes uses a method of translating your IP address to a routable address called Network Address Translation. This is where “NAT” comes from. In a typical NAT configuration, your computer appears to every other computer on the internet to have the IP address of the machine that is performing the NAT services. All your traffic goes through that machine. It keeps a table (a NAT table, strangely enough)of entries of everything you have requested from the Internet so that when the response comes back, it knows who requested it and where the response should be sent. NAT is used as a way to conserve IP addresses, as Internet routable IP addresses are neither free or readily available in huge quantities. It also provides a good level of initial security, as unless your computer requested it, it is very hard for an external co
