There are many different types of proxy servers, and all of them have their own place in the
proxy world.
Some of these types may overlap, but it is important for you to understand all of the different
types of proxies available so that you know exactly what you are dealing with when you use a proxy server.
First off, there are caching proxy servers. These are servers that, basically, retrieve saved content
previously searched by clients in order to speed up content retrieval. These are very popular for use
in large businesses, and were the very first type of proxy servers.
Second, there are Web proxies. Web proxies focus mainly on Internet web traffic, and also serve as web
caches.
These programs provide for filtering by use of a blacklist that denies access to certain
URLs. This type of proxy is used in libraries, educational establishments, and for corporate computer systems
where content filtering is needed.
Filtering may also be achieved by utilizing methods such as URL regex filtering, content
keyword filtering, or even MIME filtering. It may also produce logs to show what URLs were accessed. This is
especially popular for use in schools and other private or public organizations. Web proxies can also anonymize
web surfing by using open proxies to make themselves less visible to political dissidents or computer
criminals.
Hostile proxy servers are servers that are installed to eavesdrop on web usage and data flow. These
types of servers record things like passwords, submitted forms, and other data which can be reviewed by
the proxy operator. These types of proxies are dangerous to use, and should be avoided.
Intercepting proxy servers actually combine a gateway or router with a proxy server. These types of
proxy servers basically serve two purposes. First, they help to avoid violations of the acceptable use
policy, and second, they help to ease the administrative burden by not needing a client browser
configuration. They are commonly used in many countries to save bandwidth, and to improve the time it
takes to respond to customers.
Some proxies are called transparent proxies, and they are supposed to be proxies that do not modify the
response or the request of the data other than what is necessary for authentication. However, these
proxy servers have been known to have security flaws, so it is important to use a trusted proxy if you
go this route.
There are some proxies called forced proxies, and they are called forced proxies because they require
you to use the proxy to gain the connection, even if you do not want to use it. There are many
different types of forced proxies, and they are actually fairly common.
A reverse proxy server is a type of proxy that is installed in front of one or more different web
servers. Basically, all of the traffic coming in from the internet to one of these servers will go
through the proxy, hence the term “reverse proxy”.
A tunneling proxy server is a type of proxy server that you can use to defeat some type of blocking
policy. These servers will basically tunnel you to a site so that you can view pages you would
otherwise be blocked from.
There are many different kinds of proxy servers, and available proxy server lists on the internet; some you may
use every day and some you may never use, but they still exist, and you may even utilize more proxy networks than
you realize! More detailed information is available at Wikipedia, at: http://en.wikipedia.org/wiki/Proxy_server.
