The CryptoLab Blog

How Do They Know You Are On A VPN

How do websites know your’e coming from a VPN? The answer to that question is pretty easy…. Technology.

Companies Sell The Data

There are many companies that compile and sell IP address provider data. IPQualityScore is just one such company.

IPQualityScore maintains the most accurate database of VPN providers, including new servers and nodes that are added each day. By querying our API or processing a list of IP addresses, it’s very easy to accurately check if an IP addresses belong to a VPN provider. The VPN IP address can also be analyzed for risk analysis, location, and behavior history and similar data.

IP Blocking

A company like IPQualityScore might compile the data, but other companies like Cloudflare implement that data. Cloudflare can deny you access to a site if your IP address triggers an event. Maybe your IP address belongs to a company that hosts VPNs. One way to match an IP address to a company is via their ASN number. ASN numbers can tell other companies what their IP address might be used for. The example below is from NordVPN when I was testing out various VPN providers. While using NordVPN my IP address was blocked from visiting a site. This happed quite a few times while testing their VPN service. But what this shows is that NordVPNs IP address ( is owned by Nexeon Technologies a “Network Sharing Device or Proxy Server” service with ASN 20278.

With this information a website could block you based on knowing you are coming from a Network sharing device or proxy server.

Colocation Data Centers

A colocation (colo) is a data center facility in which a business can rent space for servers and other computing hardware. As you can see from the example below, this company has blocked the IP address range from being able to access their ordering website. You can get to their marketing side of their website using a VPN, but you can’t order food. Cloudflare has given the ability to block the IP address based on their knowledge of the IP address range.

What Is ASN?

ASN (Autonomous System Number) A unique identifier of an autonomous system on the Internet. Of the 65 thousand ASNs available, more than 30 thousand have been assigned to ISP (Internet Service Provider) and NSP (Network Service Provider). ISPs usually have only one ASN, but NSPs may have more than one.

What Is A NSP?

NSP (Network Service Provider) is an organization that provides a high-speed Internet backbone to ISPs and other service providers. Sprint, MCI and UUNET are examples of NSPs.

What Is A ISP?

ISP (Internet Service Provider) is a company such as AT&T, Verizon, Comcast, or MetroNet that provides Internet access to companies, families, and even mobile users. ISPs use fiber-optics, satellite, copper wire, and other forms to provide Internet access to its customers.

Look Up Your ASN

If you want to see who really provides your IP service, you can look them up on an ASN look up tool.


Comments (2)

  1. Cryptoroofer

    The page that you are looking for does not exist on this website. You may have accidentally mistype the page address, or followed an expired link. Anyway, we will help you get back on track. Why not try to search for the page you were looking for

Leave a comment

Other Posts You Might Enjoy