In this article I will cover about HTTP proxy only. Axtually, HTTP proxy is an IP adress. If you use proxy while surfing the net, your IP adress that is sent to the web server is changed too. This is what hackers do to make sure their their location can’t be detect.
What happens when you visit a website? Let say that you enter www.yahoo.com, these are several things that involve:
(a) Domain name for Yahoo.com is changed to its server IP adress by using Domain Name System or DNS. (actually every website have their own IP adress such as 220.127.116.11 but visitors will feel difficulty to remember those number. So domain name is created in order to resolve the numbers into words) .
(b) Web browser that you used will connect you to yahoo.com server and will send HTTP headers to yahoo.com. The headers contain several information like:
- your IP adress
- the type of your web browser and the information of your OS
- HTTP request
(c) The web browser you are using connects to the server Yahoo Dot Com is hosted on and sends an Http header to Yahoo Dot Com. In the header contains the following information
- Your I.P. Address (See below for details)
- Your Browser & Os Information
- An Http request (permintaan untuk masuk ke HTTP iaitu homepage)
*above information also is recognized as Request Field.
Then, Yahoo.com will reply by sending his homepage to the IP adress that contains in the Header.
(a) This is the fun part. If you set your web browser to use proxy, the information about your IP will not be sent but the information inside the proxy itself is sent to the proxy server.
(b) Proxy server will accept the proxy request and send you to yahoo.com webpage.
3 Level of HTTP proxy:
Level 1 Proxy:
- Also called as elite proxy
- High anonymous (surf without revealling your identity such as your IP adress)
- This proxy does not change the ‘request fiels’ and looks like real IP. Your real IP will be safe and the web admin will think that you doesn’t use any proxy.
Level 2 Proxy:
- Anonymous proxy
- Doesn’t show your real IP adress but will change the ‘request fields’. So it is possible to detect the proxy by using log analysis. There is no problem here, however there are a few admin server that prohibit the use of proxy.
- Transparent proxy
- Not anynomous (admin server can detect that you are using proxy because your IP adress is sent also inside the ‘request fields’
- This type of proxy isn’t sufficient for security purposes but very useful to improve the internet connection speed.