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Can My ISP See that I’m Using a Proxy?

I’m living in the UK, using a well-known ISP-changer program. It gives me a different ISP address that says I’m in the Netherlands, Russia, or the USA. What exactly does my own ISP see when I use this? Can they still tell how much I download for example?

This is an interesting question, particularly when it comes to understanding “IP-changing”  services.

Before I answer your questions, I need to clear up some terminology that you’re using… just to be sure that we’re talking about the same thing.

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ISP versus IP

In your question, you say that you’re “using an ISP-changer program.” I think you mean an IP-hiding service or proxy.

It’s your Internet Protocol (IP) address that’s being “changed” (hidden), not your Internet Service Provider (ISP).

The IP address is the number that identifies one end of a connection on the internet. Typically, that would be a computer or router.

Your ISP assigns the IP address to you. When you use an IP “changing” program, you’re not changing your ISP at all – they still provide your internet connection. In fact, you’re not really changing your IP address either, as you’re still connected to the internet using the IP address that your ISP assigned you.

Someone's Peeking! The only thing that changes is the IP address that you appear to be at as seen at the other end of the connections you make.

I know it sounds like I’m being picky, but when we talk about things like security, we have to use the terminology to make sure that we’re talking about the same thing.

Once the ISP assigns the IP address to you, you can’t change your IP address. The address may change at random because it’s a dynamic IP address, but no matter what IP address it is, it will be one that your ISP gave you.

What the ISP sees

If you’re concerned about what the services you connect to can see, you can use a service (like you’re doing) that masks your IP address. These are called proxies, tunnels, or virtual private networks, depending on the specific technique that they use. (“IP changing service” is actually a rarely used, and inaccurate phrase.)

When you select one of these, your IP address doesn’t change, but you appear as if you’re coming through the IP address used by that service, not your own. All of your communications then route through that service.

Now, what your local ISP can see depends on what you’re doing and which technique you’re using.

First, they can always tell that you’re connecting to one of these proxying or anonymization services.

If it’s a simple proxy, they may be able to see what you’re transmitting.

If you’re using an encrypted VPN, then they would only see that you’re using a VPN and not the contents of the transferred data. Still, they would see the amount that’s being transferred because they are still the ones that provide you your connection to the internet and transmit to your computer all the data involved.

Like I said, it’s important to use the right terminology when you’re talking about anonymization. Whether you’re trying to hide from aggressive government enforcement or just view a video that’s blocked in your country, the needs and requirements for anonymization depend on you knowing the difference. Once you understand that, you should be able to set things up just fine.

Posted: September 12, 2013 in: Network IP Addressing
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17 comments on “Can My ISP See that I’m Using a Proxy?”

  1. You got to realize that no anonymization service is 100% watertight.
    Just depends on the money, and efforts, the adversary is willing or capable to use to spy on you.
    A work around might be to install the anonymization program on a thumbdrive for use in a internet cafe, or access the internet from another location (wifi spot, and such). That’s a shure thing to hide your physical address.
    And disable javascript of course.
    But remember the NSA has backdoors in most operating systems in use nowadays.
    So if you’re really into something meet-up instead of web-up.

    • I don’t believe that “the NSA has backdoors in most operating systems in use nowadays” at all. If they have access anywhere it’s much more leveraged at the ISP/infrastructure level. Even there I don’t think things are quite as bad as most of the current alarmist news would have us believe. Not that things aren’t bad, but not “eavesdropping on everyone” bad. We’re just not that interesting.

    • There is planty of free open source OS that NSA or any other agncy upper hand on it , pickup the one you want and monitor traffic with 3d part hardware tools and see if anyone realy spy on you .

  2. good article I have actually been curious about that for a while, if an ISP such as comcast could see what was going on to and from the router to the vpn, I always assumed they could and the only way around that would be to setup and entire vpn server in my home before their router, to be honest they can keep watching me they already have my account numbers.

  3. My question is then, if you were to create your own VPN in your home and have it connected to your ISP gateway, could they not still see were you are going? The VPN connection still has to go through their network. Were as if you were to pay for a VPN service they would see you connect to a VPN rather than seeing your VPN connect to were ever you were visiting. Is my logic correct?

  4. How to hide data from aggressive government enforcement. In my part of the world i can see, i can listen but i cant speak. Even i am scared to say a thing against aggressive government enforcements on twitter or Facebook. If i use TOR to reach twitter or Facebook with a fake ID can my ISP track me and my contents of speech? If my opinion is not liked by aggressive government enforcements would they be able to track me and put me in their torture cells.

    • This is a relevant question in all parts of the world, as we see growing, totalitarian tendencies, also in Western countries.
      I am here out of the same concern.
      Thank you for your bravery, Faheem. Freedom of opinion and freedom of speech are important, basic values that need protection, and so do we.

    • Yes if you use Tor and they know they will brick your desktop or laptop computer
      also with all them people working at Ft. Meade, you will get caught and if you’re
      game enough you better use a crap laptop because if you use a new computer
      say good by to it unless you have information in it you need don’t chance it,.

  5. A VPN encryption service or proxy server, whether its your own or purchased online, hides the websites you are visiting from the ISP. The real question I have is, does the ISP have legal authority to deny your service if they cannot “see” the websites your visiting.

    • “Legal” -> I am not a lawyer. However I would expect that, yes, an ISP has every right to control how you use their service. All part of the terms of service you agreed to when you signed up.

        • It would have nothing to do with net neutrality. Your ISP is providing your internet connection. They are actually the service that sends you to different pages on the internet, so obviously their equipment can see where you are going. The likelihood that some human being is sitting there watching you is very slim – unless you are a high profile figure or doing something illegal.

          • It’s not like someone is re watching you’re every move. An analyst will likely look at numbers, notice something out of norm, and start monitoring irregularities. So if you’re online behavior is in line with the average user, it’s unlikely a gov employee will be peering in.

            I suspect ISPs work very closely with the gov. For example, if they notice that a customer is connecting to multiple proxy servers frequently and everyone else in that area is in the norm, they could tip the the gov and let them slip into their back door and access data.

            ISP already has all your info: name, address, etc. Now gov can start monitoring. A tiny slip up can give them information. Don’t forget about the PATRIOT act (if you’re a U.S. citizen).

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