Difference Between NAT and Proxy

NAT vs Proxy

Network Address Translation (NAT) is the process that modifies the IP address in a header of an IP packet, while it is travelling through a routing device. NAT allows one set of IP addresses to be used for traffic within a LAN (Local Area Network) and another set of IP addresses for outside traffic. One to one transformation of IP addresses are provided by the simplest form of NAT. Proxy (proxy server) is a server that is located between a client (who is looking for a resource) and some other server and acts as a mediator. The client requesting the resource connects to the proxy server and the proxy evaluates the request based on its filtering rules.

What is NAT?

NAT modifies IP address in a header of an IP packet, while it is travelling through a routing device. NAT allows one set of IP addresses to be used for traffic within a LAN and another set of IP addresses for outside traffic. One to one transformation of IP addresses are provided by the simplest form of NAT. NAT has several advantages. It improves the security of a LAN since it provides the option to hide internal IP addresses. Furthermore, as the IP addresses are only used internally, it will not cause any conflicts with IP addresses used in other organizations. Also, using a single internet connection for all the computers in a LAN is made possible by NAT. NAT works with the use of a NAT box, which is situated in the interface where the LAN is connected to the internet. It contains a set of valid IP addresses and it is responsible for performing the IP address translations.

What is a Proxy?

Proxy is a server that is located between a client (that is looking for a resource) and some other server and acts as a mediator. The client requesting the resource connects to the proxy server and the proxy evaluates the request based on its filtering rules. If the request is validated, proxy connects to the server and provides the requested resource to the client. On the other hand, proxy may satisfy the client’s request without going to the specified server. For this, the proxy uses a cache and any of the subsequent requests for the same resource are satisfied without contacting the specified server. Due to this, proxies can improve the performance greatly. Furthermore, proxies can be used to filter requests and prevent accessing some web sites.

What is the difference between NAT and Proxy?

NAT modifies IP address in a header of an IP packet, while it is travelling through a routing device and allows to use a different set of IP addresses for traffic within a LAN than the set of IP addresses for outside traffic, while a proxy is a server that is located between a client and some other server and acts as a mediator. NAT does not need any special application software to operate, whereas applications behind a proxy server must support proxy services and should be configured to use the proxy server.

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