Question on Proxies

[kumarkumar]

This may be a stupid/lame question since I am not so familiar about proxies.

What actually happens when I configure my internet connection through a random proxy server. (in IE using properties->connections->LAN Settings->Proxy server)??

Specially in the case while downloading something.

My idea is, proxy is kind of a middle-man. So it would be something like this.

Say my computer is "A" and I am accessing a website whose server is "B". And I am using the internet connection from an ISP named "X". There is somewhere a proxy server whose server is "C" and who uses the internet connection from an ISP named "Y"

Case 1: During a direct connection.

"A" accesses "B" directly using the connection from "X" utilizing "X"'s bandwidth.

Case 2: During a connection though a proxy server named "C"

"A" accesses "B" but through "C". So the connection goes like "A" to "C" and then "C" to "B".

Now "A" connects to "C" using the internet connection from ISP "X", hence utilizing "X"'s bandwidth. But when the connection occurs from "C" to "B" does it use the connection of the ISP "Y"??

So when I am downloading something using the proxy server "C" am I utilizing the resources of the internet connection of "C"?? Am I utilizing the bandwidth of "C"'s internet connection "Y"??

[LLXX]

http://en.wikipedia.org/wiki/Proxy_server

Read and be educated.

[ringfinger]

Dude, you're making this way more confusing then it has to be. You are right in thinking that it could be considered a middle man however. Think of it this way, your at work... they don't want you looking at porn, active directory forces the networked users to pass through x.x.x.x proxy server. So now when you go to the net, you're authenticating to the proxy, its saying ok you're good to go, depending on the server it does a many-to-one translation and pushes you out on the public side of the network. All the while blocking and only allowing you to see what it wants.

People commonly use anonymous free proxies to spoof their true IP on the net, I suppose it makes them feel like they're in the NSA and high tech or something.

Lastly, no... you're not using that servers particular 'bandwidth' so to speak.... you have your cap on your connection as does this server, wherever it may reside. You are using a portion of the bandwidth while it processes your requests, but would never be 'inheriting it's speed'.

[tain]

Case 1: During a direct connection.

"A" accesses "B" directly using the connection from "X" utilizing "X"'s bandwidth.

So the question here is...?

Case 2: During a connection though a proxy server named "C"

"A" accesses "B" but through "C". So the connection goes like "A" to "C" and then "C" to "B".

Now "A" connects to "C" using the internet connection from ISP "X", hence utilizing "X"'s bandwidth. But when the connection occurs from "C" to "B" does it use the connection of the ISP "Y"??

Yes.  Bandwidth is being used by both A/X to C/Y and C/Y to B.

So when I am downloading something using the proxy server "C" am I utilizing the resources of the internet connection of "C"?? Am I utilizing the bandwidth of "C"'s internet connection "Y"??

Yes and yes.  Bandwidth is being used by both A/X to C/Y and C/Y to B.

Think of it as a chain.  The bitstream flows along all those links as you described them.  If C/Y is really slow (weakest link), your connection will be really slow.  But if C/Y is really fast, as "real servers" tend to be, then it should be able to serve the data to you as fast as your A/X connection (weakest link) will allow.  This is why caching proxies are popular.  If the proxy caches all the data from one person's request, then it can be served to the next requester from the cache without using any of C/Y's outbound bandwidth again.

Be careful with that "random proxy server," though.  People like to trade lists of open proxies to use for anonymity or whatever other reasons.  That does shield you from "B," but the proxy "C" sees all of your data and knows who you are.  You may be slowed by that proxy if it is overloaded or on a slow server/connection.  And perhaps that proxy has been setup honeypot-style just to see what people (you?) are doing.  You never know!

[kumarkumar]

Thank you very much TAiN,

That was exactly the answer I was looking for.

Edited December 28, 2006 by kumarkumar

[kumarkumar]

Hey TAiN,

One more question. The free proxy lists (whether anonymous or transparent) you get when you search in the net......are they really free to be used as proxies.......I mean do I have their consent to use them??

This is because since I am utilizing their resources/bandwitdh.

(Most of them are govt institutions, universities, big ISP's.)

Edited December 28, 2006 by kumarkumar

[tain]

I mean do I have their consent to use them??

That depends on your perspective of the legal system.  Some people equate such things to light.  As in, "I can use someone's porch light to read a book (trespassing aside) and that is legal."  That line of thought tends to lead to jail.  You'll see on the news all the time about people getting busted for stealing bandwidth, usually via wireless.  (But it does tend to be in conjunction with some sort of deviant behavior like driving around naked.) Do the people with the unsecured wireless APs get in trouble?  No.  So, no; you probably do not have their consent just because it is "open."  But I don't think many people get busted for using open proxies, if that matters at all.

I'm not really sure what you are pursuing here.  Speed?  Anonymity?  Perhaps you should read up on Tor.

[kumarkumar]

You'll see on the news all the time about people getting busted for stealing bandwidth, usually via wireless.

Wow never knew that....

I have never used a proxy before (never needed to use it). Used it for the first time yesterday just to get a feel of it.

Let me tell what happened. I took a random proxy from the net and started to download a Linux distro (~700MB). (Since I was not aware that I was actually utilizing their bandwidth so I took the liberty to download ~700MB)

The download continued till the half of it and then stopped. I tried to start the download again but it would say "not able to connect". So to check it I tried to download it with direct connection. It downloaded completely.

The proxy server was not down, since it would let me surf the net. But it wouldn't let me download henceforth.

So all these above questions came to my mind, and for the sake of getting my fundamentals right I am asking these questions.

Shortly after this happened I read all I could about proxies including Tor.

Now I think that the proxy server might not be free to use. So it got p***ed off since I was utilizing a lot of their bandwidth and hence it blocked downloading (may be specifically for me or my IP).

Could this have happened??

Edited December 28, 2006 by kumarkumar

[McTavish]

This is by a company that sells a proxy service, so maybe it is hyped a little bit, but everything in it is true.

http://theproxyconnection.com/openproxy.html

[kumarkumar]

Thanks a lot McTavish for that link.

Wow.....that was enlightening and indeed very scary.

But as you said it may be hyped a little bit since it was like an advertisement for that company.

But anyways I guess whatever it talked about made sense.

I am not going to use any proxies henceforth. Now I am sure most of the working proxies that I find listed on websites like

http://www.proxycn.net
http://www.xroxy.com/
http://nntime.com/

etc, etc are open. And when I checked the Whois of these working proxies most of them turned out to be universities and govt organizations. So may be these are honeyspots. Better not to fall in any of these spots either hacker or honey.

[McTavish]

If It's just for privacy reasons then hiding your IP address is not the way to go. See this thread.

http://www.msfn.org/board/index.php?showtopic=88851&hl=

[LLXX]

In particular: http://www.msfn.org/board/index.php?s=&amp...st&p=600121

Regarding legality - many people download MP3s, software, etc. from P2P networks. Is it illegal? Yes. Is the risk of getting caught high? No. Do they still do it? Yes. Same with public proxies.

If you really want anonymity you can use Tor, but it's too slow for regular browsing use.

[kumarkumar]

Thanks McTavish & LLXX.

http://www.msfn.org/board/index.php?showtopic=88851&hl=

looked a bit technical too me.

You could spoof a Forwarded header in your requests so that it looks like your real address is a proxy and the spoof is your address.

I will have to read about these before I could actually carry it out on my computer.

But if you guys could show me how to do it, that will be quicker.

Edited December 31, 2006 by kumarkumar

[LLXX]

You can use Proxomitron to do that.

[McTavish]

A4Proxy can also do it, but there must be others. Don't know if it can be done without a third party app.