Proxy definition and function and how Proxy works in computer network

When someone through their personal computer using a proxy Internet network is trying to surf the internet, the user's computer identity (IP address) will be visible to the website requested.

Sometimes, if you are not careful, this IP address can be misused by others, such as to spread viruses, malware, or even retrieve personal user data such as email passwords, bank passwords, and so on.

To prevent the user's IP address from being clearly visible, we can use a proxy that bridges the personal computer with the Internet network. The following will be explained in more detail regarding proxy definitions, proxy functions, proxy types, and how it works.

Proxy definitions
Simply put, a proxy is a computer server that serves to forward user requests to other servers on the Internet. In the same time, this proxy server is a connection between personal computer and Internet network. Proxy itself has several kinds of usability, among others:

1. To hide the IP address of the client/user's computer, so anyone can surf anonymously without leaving a trace of the IP address on the Web page visited. For example, if a client visits Google through a proxy server, then Google will see that visiting it is a proxy server, not the client, so that Google can also not track the user's client position.
2. Surf faster on the Internet. All requests from client computers will reach the proxy server first. Then the proxy will check if the Web page that the user visited already has caching stored or not. If there is, then the client will get feedback from the data caching, so that the client can surf faster on the Internet.
3. To block an unwanted site. Suppose for the Internet network in offices, so that workers in the Office do not utilize the Internet to play social media and watch, then some sites can be included in the blacklist proxy so that it is not accessible through the office network.

Proxy function

There are several proxy functions that need to be understood, including connecting sharing, filtering, and caching. More details about the three proxy functions will be explained in the following points.

1. Connecting Sharing
Proxy function for connecting and sharing. That is, with a proxy, then an IP address of the user's computer can be connected to another IP address, can also be an intermediary to share data between two IP addresses.
In the function of connecting sharing, a proxy can be a gateway that restricts local networks and outside networks. With the connection Sharing function, a computer is very likely to connect from a local network to the Internet using the gate connection.

2. Filtering
Some types of proxies also come with a firewall that functions to filter out unwanted IP addresses, even blocking them from preventing damage to the computer.

For filtering function, the proxy works on the application layer, to protect the local network from a wide range of attacks and possible interference from the outside network. To reject a specific IP address at a time, computer users can configure the proxy.

3. Caching
Caching means that the process for a proxy stores data that users have already requested while browsing the Internet. For example, when we open a website that contains images and objects in it, then the image data and the object will be stored in the cached form. The existence of data storage of a web on a proxy makes users faster to access the website, especially if the previous proxy users already have access request for the website.

Types of proxies
Based on its characteristics, at least the types of proxies can be divided into four kinds, namely Anonymous Proxy, High Anonymity Proxy, Transparent Proxy and Reverse Proxy. Here is an explanation of these types of proxies.

1. Anonymous proxies/proxy: This type of proxy is a proxy type that will notify the user's computer information. When a user requests a website, the website will know the proxy IP address used by the user, but does not know the user's personal IP address. Because the website server can not access the user's IP address, then the communication between the user and proxy server is encrypted so that security is also assured.
2. High Anonymity Proxy: This type of proxy does not identify itself as a proxy server, so it does not provide the original IP address. This type of proxy uses the REMOTE_ADDR header with an IP address to the proxy server, so that from the user it will be visible that its server proxy serves as the client.
3. Transparent Proxy/Transparent Proxy: A simple example of a transparent proxy is a server that resumes the user's request to the desired source without revealing the user's computer information. This transparent Proxy is pretty much applied in office, where every IP address that performs request visible by the server through HTTP headers.
4. Reverse Proxy: This type of proxy is generally used to provide a way over various user requests from the Internet, through an isolated firewall and a private network. Reverse proxies are widely used to prevent clients on the Internet from connecting with unmonitored access, which involves content sensitive data from a closed network such as an intranet. If caching on reverse proxy is enabled, network traffic can also be lowered.

How proxies work
The proxy then forwards this request to the Internet network, as if it were not the requesting user, but rather a proxy server. Then once the proxy manages to find what the user needs, the proxy will respond to the user.

That's the explanation of proxy definitions, proxy functions, proxy types and how it works. Of course using a proxy or not returning to your decision, but if a computer network consists of many clients such as in offices or companies and do not want the internet to be used for things that do not support productivity, then there Good to consider installing a proxy.