Then what is a proxy server?
Proxy servers are a stand in dedicated computer or software system virtually
located between a client and the actual server.
It acts as a sentinel between the... That's a cool term.
Sentinel between internal network and open internet.
It's a Guardian. It's a gatekeeper.
It is exposed to the public internet,
but it shields your identity from exposure to the public internet.
When we talked about firewall configurations, earlier in the module, we
mentioned a couple of different types of proxies.
Again, the proxy is a stand in.
It's either transparent or non transparent.
In transparent, the client system connects to a server without its knowledge.
It's configured to be entirely invisible to the end user.
With the transparent proxy, all the web clients must be configured manually.
There is no indicator in the packets that you're being proxied.
In a non transparent proxy, client
software needs to be configured to use the proxy server.
The client is made aware of the proxy server's existence.
They're more difficult to configure.
Client program must be set up to route all request to a single port.
There's also anonymous versus non anonymous.
Anything that's transparent, let's talk about transparency for just a second.
Transparency is unknown to the user.
Transparency is desirable with security controls because if you don't know they're
there, you don't know that they need to be circumvented.
When your client system automatically
connects that proxy, that could be a proxy auto detect, something like that.
All the web clients must be configured manually.
The actual detection piece might be unknown to the user.
In a non transparent where you actually
have to configure a program to connect to it, it's pretty obvious it's there.
Then you also have forwarding information
and the packet contents, which you may see exported four types of headers in HTTP.
A SOX proxy.
Sox is an IETF standard.
It's a proxy server that doesn't have
caching capabilities or abilities of an HTTP proxy server.
It does not allow external network
components to collect information on the client that generated the request.
So you see SOX proxies used for all sorts of proxy implementations.
A lot of your proxy chains utilities will use SOX based proxies.
It requires a server, intermediaries, and a client for connecting to it.
An anonymous proxy versus non anonymous
does not transfer information about the IP address of its user,
therefore hiding information about the user and their surfing interests.
You remain anonymous behind the proxy,
which those proxies are going to implement a degree of anonymity.
The non anonymous proxy will actually
include potentially, again, like I mentioned earlier, exported information on
the client or the internal client that requested the connection.