Nat; Network Address Translation - D-Link DFL-600 User Manual

NAT

Network Address Translation

Note: NAT is automatically applied between the WAN and the LAN sides of
the DFL-600. It does not require any user configuration.
Network Address Translation (NAT) is a routing protocol that allows your
network to become a private network that is isolated from, yet connected to
the Internet. It does this by changing the IP address of packets from a global
IP address − assigned by your ISP − usable on the Internet to a local IP
address − assigned by you − usable on your private network (but not on the
Internet.)
NAT has two major benefits. First, NAT allows many users to access the
Internet using a single global IP address. This can greatly reduce the costs
associated with Internet access and helps alleviate the current shortage of
Internet IP addresses. Secondly, the NAT process creates an added degree of
security by hiding your private computers behind one IP address. The NAT
function will normally only allow incoming packets that are generated in
response to a request from a computer on the LAN.
NAT is automatically applied between the IP addresses assigned to the DFL-
600's WAN port (the IP address or addresses assigned to you by your ISP)
and the IP addresses assigned to the DFL-600's LAN ports (the 192.168.0.x
subnet). NAT is not used between the WAN port and the DMZ port.
Complications with Using NAT and Some Applications
NAT is a simple IP address mapping function (that is, it only looks at IP
address headers) and is therefore unaware of the application data embedded
in packets that pass through it.