Proxy Servers – Forward & Reverse Proxy Servers

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A proxy server is similar to a web browser.  Whenever you look at a web page, your web browser stores that web page into a cache, so that at a later time, if you are to look at the web page again, your browser retrieves it much faster. This increased speed comes as a result of the fact that the browser doesn’t have to download the contents of the web page all over again, given that it’s already stored on your computer.

A proxy server does the same thing. For example, if a company uses a proxy server, then whenever a user wants to view a web page, the proxy server will retrieve the web page from the internet on behalf of the user, and will then enter that same web page into a centralized cache database, so if another user on a different computer goes to a web page that has been stored on a proxy database, the proxy server does not have to venture out into the internet to retrieve the web page.  It can just retrieve it from its corresponding location in the database and send it to the user.  Keeping that in mind, we can understand that one benefit of using a proxy server is speed, since web page retrieval is faster.  Another benefit is that it saves bandwidth because the proxy server reduces the need to go out into the internet.  Finally, it also offers increased security, because it reports which web pages are being retrieved to the network administrator.

A proxy server will protect our identity from another party—indeed, that’s one of its main functions.

Some of the functions of a proxy server are:

  • Proxy servers help obscure the client’s IP address and their identity.  The proxy server passes the messages from a private IP address to a public IP address.  The public IP address is the one which is routable to the internet, and can therefore send and receive information in concert with other servers out in the internet.  When a user requests a specific web page, it will be sent to a proxy server, and the proxy server will pass on the request on the user’s behalf. The proxy server will also remember who sent the request out, and it will pass the request on using its public IP address, so that the web server can respond to the request.  The message / request will come back to the same IP address, so that the proxy server knows who requested the information originally, and it will properly route the data to the user as needed.  Throughout this whole process, the web server doesn’t  need to know the specific identity of the user, ensuring anonymity and privacy.
  • Another main thing that a proxy server can do is to help block malicious traffic.  It essentially obscures your identity, so it’s not readily apparent how to go about attacking you.  The hacker might know the company and want to attack a specific computer belonging to the company, but since the computer is on a private IP address, the hacker will only be able to attack the proxy interface. The attack will stop there, because it cannot proceed any further.
  • Proxy servers also help to block sites.  If a user is trying to access a forbidden web site, like a prohibited site, rules can be set up on the proxy server that will block traffic to those specific sites.  So proxy servers have whitelists, some have blacklists, and some have regularly updated lists for still other categories of web content.
  • Proxy servers can also log activity. Not only will they identify which websites you visited, but also those websites which you tried to visit but had been blocked from.  It can even identify how much time a user spent on a certain website.
  • Proxy servers improve performance.  The proxy caches data when it first retrieves content from one web site, so when another user needs to access the same content it doesn’t have to go to the internet, but rather just needs to find a way to access the cached data.