We have in this chapter in detail explained NAT and the theory around it. In special we have discussed a couple of different angles to use, and some of the normal problems that may arise from using NAT together with proxies. This chapter has covered the following areas in detail.

NAT usage

NAT components

NAT history

Terms and words used about NAT

Hardware discussions regarding NAT

Problems with NAT

All of this will always be of use when you are working with netfilter and iptables. NAT is very widely used in today's networks, even though it is only an intermediary solution for a very unfortunate and unexpected problem. NAT will of course be discussed more in depth later on when we start looking at the Linux netfilter and iptables implementations in more depth.