How A Proxy Server Works?

proxy server

HTTP access via proxy server

A proxy server, or proxy for short, is used to allow users within a firewall to access the WWW. A proxy server is a special HTTP server that runs either on the firewall machine or on another Internet-based computer within the firewall.

If a client wants to retrieve a document from the WWW server on the Internet within the firewall, it will contact the proxy server. It accepts the request, forwards it to the server outside the firewall, reads the response of the remote server and then sends it back to the requesting client free proxy.

The proxy server acts as both client and server in this type of communication. Compared to the requesting WWW client, it behaves as a WWW server, compared to the remote server as a client.

The client request header is used by the proxy unmodified for its request to the remote server, which causes the WWW client not to lose functionality when using a proxy server.

Because the WWW supports other Internet services, the proxy server is able to act as a gateway to other information servers such as FTP, Gopher, WAIS or news servers. It shows that the communication between client and proxy is always handled via the HTTP protocol.

The proxy communicates with the remote server via the respective protocol, in this case via the FTP protocol. In addition, the proxy server must convert the objects it receives from the remote servers into HTTP objects before sending them back to the WWW client.

By using a proxy server, access to Internet resources can be controlled and restricted. Access control can be based on access method, IP address, or domain name.

This means, for example, that the proxy server only allows some special computers in the local area network to access the Internet in order to prevent unnecessary costs arising from improper or unintentional use of the Internet.

Code Of The HTTP Transaction

In addition, the WWW access behavior of the local users can be analyzed with the help of a proxy server at the Internet transition. The proxy records client transactions for this purpose. An entry in a log file contains, for example, the IP address of the requesting client, date and time, the URL of the requested object, the size of the transmitted data in bytes and the status code of the HTTP transaction.

In addition to these advantages, the use of a proxy server on the firewall machine also has a major disadvantage.

Since the firewall is the only point of attack of the local network in relation to the Internet, as few security-related applications as possible should run on the firewall in order to minimize any potential security gaps.

Because the more extensive a software is, the more likely it is that it contains errors and thus security holes. For example, if the CERN server is used as a proxy server on the firewall machine, it represents a potential attack target from the outside.

Gain Extra Protection Through Reverse Proxy

Reverse Proxy – The Extra Protection

reverse proxy

Many companies operate their web servers in their own data center. Firewalls have long been standard, as well as DMZ networks that contain only servers that are to be accessible via the Internet.
In addition to the firewall, however, there are many other protections that should not be ignored. These include virus scanners and operating system updates (especially security updates) on the web servers. In this article, I introduce you to another protection mechanism.

The reverse proxy, Proxy server
Proxy systems were originally used as caches to avoid having to download data multiple times from the Internet. This proxy server has stored web pages, images and downloads downloaded by users of a local area network and made them accessible to other users at high speed. In the foreground was not only the download speed, but also the required bandwidth of the external connection of company networks. With increasing bandwidth, proxy servers have become more and more in the background.

Another advantage of a proxy server is that users do not need direct access to the Internet, which provides increased protection against Trojans or malicious software that takes contact from the internal corporate network to the Internet.

Reverse proxy server

A reverse proxy does the same thing as the proxy server, just the reverse. Users from the Internet access the in-house Internet server via the proxy server. Thus, a hardened operating system without additional functionality (database systems, file servers, etc.) can be made available as an access point for Internet users. This avoids the constant security updates on the production systems (which in part also affect their functionality), as Internet users only get access to a reverse proxy server. This then forwards the requests from the Internet to the appropriate internal web server.
Network overview DMZ with reverse proxy
The Reverse Proxy accepts all requests and forwards them to the production systems. Thus, the client never communicates directly with the server.
It certainly makes sense to use different operating systems for reverse proxy and production server.
Extended access control
With the proxy site, further access controls can be made. CMS systems usually have an area for data maintenance that is protected by a password. However, these systems are only ever as secure as the passwords given. To increase access protection, certain paths can only be accessed internally via the proxy server.
For example, if Typo3 is used, the administration path is in most cases With a reverse proxy, access can be controlled so that this administration path can only be reached from the internal network, and not from the Internet.
With a reverse proxy site several internal systems can be made available via the same external IP address. The proxy server then takes over the routing to the corresponding systems. In a next blog article, we will provide you with an example configuration for using a Squid Proxies.

The Ananymity Of The Proxy Server

proxy server

How The Proxy Servers Maintain Their Ananymity

Proxy servers maintain their anonymity when you surf the Web, or unlock videos and information that are not available due to country blocking.

To watch videos locked on YouTube, you need a proxy server that will serve you as a surfer from another country. Even if you do not want to be followed by all sorts of websites while surfing, a proxy server helps maintain your anonymity.

A proxy server can do a lot more. What a proxy server is, how it works, what it does for tasks and when it may well be worthwhile for you to use a proxy server – read on the following pages.

A proxy server is a proxy who shares a communication in two separate calls. Router and proxy server.

While the router connects directly between your home network and a web server, you are anonymous behind a proxy server. Filter content.

A proxy server can manipulate the answers of the web server before passing them on to the PC Anonymization, Dividing a communication into two or more separate calls can also be an advantage for you: The web server sees only the proxy server, but not you.

Proxy Server,  Proxy In The Network 

All the basic technical details about proxy servers and proxy site are explained in the image section of the professional knowledge “proxy server – proxy in the network” . In the following, you will learn what a proxy server actually is and how it can be used at home or in the company.

What is a proxy server?

A proxy server is a proxy in communication with other computers in a network. Substitute because the PC and the server never communicate directly with each other. Instead, the proxy server always acts as the communication partner of the PC and the server and thus becomes part of the communication itself.

PC becomes invisible to the server

Normally a PC sends, if a web page should be opened, the request directly to the server. The server in turn sends the requested website to the PC. PC and server communicate directly with each other.

If, however, a proxy server is used, then the PC sends all its requests to the proxy server and no longer to the web server. The communication to the web server is handled by the proxy server.

He accepts the request from the PC and in turn makes a request to the web server. The answer from the web server initially resumes the proxy server. Then the proxy server turns to the PC and sends it the response received from the web server.