What is NAT
NAT Network Address Translation is a very important concept in the field of the Networking. In the field of networking two of the most important troubleshooting problems are of IP address depletion and Hiding the Original IP address from sniffers.
The concept of NAT is basically employed to handle the above mentioned issues, now following is the explanation how the NAT counters these issues. Now we categorize the NAT into two categories Static NAT and Dynamic NAT
firstly taking about the network security by hiding the IP address, it is done under the Static NAT, in this case one IP address is mapped to the other IP address, that is in this case we are masking the IP address with some other IP address, for example suppose there is a IP address as 220.127.116.11 and we want that the exact address should not be displayed to the outside world but the services must be as they were by using the original IP address. Suppose we have mapped this IP address to another IP address as 172.19.2.10, then from now onwards this website would be available to all outside users as on IP address 172.19.2.10, and this is made possible by making use of NAT. and process is known as Static NAT.
Now dealing with the dynamic NAT, it is used to solve the problem of the depletion of the IP addresses by mapping number of private IP addresses to a public address. The concept works as follows we decide a pool of private IP addresses. A private IP address is one which is used within a campus of a Ethernet and these IP addresses cannot be routed on the internet, These IP addresses need not to be allocated by the ISP and can be directly implemented by any of the organization. Every class of the IP address has some of the IP address reserved as private addresses. Now the question is how this technique solves the problem of the IP depletion, so answer to this question is the private IP addresses used within a campus can also be used by some other campus. This concept uses the technique of the reusing of the same IP addresses at different locations. After deciding the private address pool we map those IP addresses to the public IP address and then the request id forwarded on the internet. For a private network the public address acts as the gateway and NAT is used to map the private addresses to public address and solve the problem of delpition.