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Can My ISP See I’m Using a VPN?

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Can my service know if I’m using a VPN? Thanks.

The exceptionally short answer is: yes.

Let’s look at exactly what VPNs expose to your ISP that allows them to figure it out.

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Connecting to a VPN

There are two characteristics of a VPN that cannot be hidden from your ISP:

  • The fact that you are connecting to the IP address owned by a VPN service.
  • The fact that your software is connecting to ports associated with standard VPN activity.

Your ISP is responsible for taking a packet of data from you and sending it where it’s supposed to go. The only way it can do that is if it knows where the packet is supposed to go. If you’re using a VPN, that destination will be the VPN’s servers.

VPNIn fact, it’s possible that — even though your data is encrypted — the packets of data have overhead information that could also be used to make the determination that it’s travelling over a VPN.

Attempts to hide further

I often see comments that by using a port more commonly used for other purposes — for example, running a VPN over the ports more commonly used for webpage traffic — can hide the fact that you’re using a VPN. This is actually not the case. Your ISP can still see that you’re connecting to a server associated with a VPN service, even if you’re using a non-standard configuration.

Alternate ports and other configurations attempt to bypass firewall rules that might block standard VPN ports. Unfortunately, this remains only partially effective, since the firewall can still see and block access to the entire VPN server.

What the ISP cannot see

It’s important to realize while your ISP can see that you are using a VPN, they cannot tell what you are using it for.

For example, you might connect to askleo.com through your VPN. Your ISP can see only the VPN portion. That you are connecting to askleo.com, and the information being sent to and from askleo.com through the VPN, is encrypted and inaccessible.

Remember, however, that your VPN provider can see everything, just as your ISP might otherwise. In a sense, your VPN is acting as your ISP, as they’re providing the final connection to the rest of the internet.

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12 comments on “Can My ISP See I’m Using a VPN?”

  1. Thanks for the reply. It has been very usefull as some of my friends use VPN in Middle East Arab countries like UAE and Oman where you can get jailed and / or heavily fined for using a VPN

  2. Hey Leo. I use an old freeware version of Hamachi VPN (version 1.0.3.0) which is “out there” on sites such as http://www.OldVersion.com.

    It creates TCP/IP addresses in the non-existant range of 5.x.x.x. My own individual Hamachi address is 5.139.149.149 – however I have complete annonimity from the entire world because only other computers running Hamachi can even see a 5.x.x.x address and, even then, they can only see my individual Hamachi address if they are a member of my heavily passworded group however I’ve also gone into Hamachi’s properties and turned off a feature that denies access to any new group members.

    It’s very fast point-A to point-B and I’m entirely protected and encrypted within my own “regular” isp’s normal IP address range and I’m completely legal and doing nothing wrong.

    I am a computer software designer for small businesses and have Hamachi and UltraVNC running as system services totally silent witout even system tray icons on all of the nearly 200 PC’s that I support. As long as these PC’s are turned ON I have direct 24-7 unattended administrator’s access to them including bi-directional file transfer.

    Also you can map a drive to any PC with a shared hard drive within your Hamachi group.

    It’s not like being connected with Cat-5 cable when you start manipulating distant accounting files but a true dedicated point-to-point VPN can cost $1,000 per month. Free is good.

    Note: Does NOT support AERO – but most of my customers are still running XP Pro and they have thankfully allowed me to set their screen attributes to “Classic” with a plain black background & no wallpaper. All of these video tricks REALLY make the old UltraVNC running over Hamachi trick work at pretty decent speeds. Any of you needing help with this setup please feel free to email me {email address removed} for free advice.

  3. Have slow isp 1.5 m can’t get any faster where I’m at , can I get any faster service on VPN ? If so how much would I need to pay ?

    Since a VPN runs on an existing internet connection, it’s limited in speed by your internet connection. It will not speed anything up.

    Leo
    02-Oct-2012

  4. Hi Leo,

    I am an independent contractor working from home. My personal computer is set up with a VPN connection that accesses company files through Goldmine. Also, my business emails are set up through Outlook and routed through the company’s server. I understand that they can see my business emails and track my activity on the VPN, of which I have no issue.

    However, I use one computer for everything and do not want them tracking my “personal” activity, especially since I am not an employee. I do not access the Internet through their VPN. I have my own connection through AT&T and use Outlook Express for personal emails.

    My question is this: When I am logged onto Goldmine through the VPN, can the company view my other activities through my own personal Internet connection and personal email? They claim that they can only see what I am doing specifically on the VPN and nothing outside of that portal.

  5. Hi Leo,

    I have used SSL VPN from {url removed} VPN provider.
    It worked using 443 port.

    So it’s not looked like VPN connection.
    Many usual websites using https (443 port).

    But one weird thing – SSL VPN working only on Windows Vista, 7 and 8 🙁

    Also you can use OpenVPN on any port. For example on port 80 🙂

    I believe it can’t be detected as VPN connection 😉

  6. This also works in the other direction. Websites you visit via a VPN can determine that you are visiting them via a VPN, and sites like Netflix block access to traffic from what they identify as a VPN.

  7. I use a VPN to help hide who and where I am etc. no problem with it but a simple question pops up in my thinking section.
    Why don’t ISP’s run their own systems as VPN’s? It would negate the need to run a third party to provide the invisibility that VPN’s provide.

  8. I purchased 2 years of service from Nord VPN. Nord uses Open Proxies in the US and elsewhere to facilitate their service. Just months into my VPN subscription the FCC, in their ill-conceived bid to reduce regulations, threw out Net Neutrality rules intended to keep the Internet free of interference from ISPs. As a result, my ISP filters traffic for Open Proxy IP addresses. Now I can no longer use Nord VPN because, within minutes of connecting to Nord thru their client, the connection stops working and all I get are “Connection timed out” errors. Basically, now ISPs may do whatever they want and my ISP doesn’t want me using a VPN. Thanks, orange man.

  9. Is there any way to hide my connection from my ISP I know that a VPN will hide my browsing data but can I hide even the fact that I am connect ted from them?

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