How does a VPN Protect You From Your ISP?

4 min

Internet Service Providers (ISPs) are crucial enterprises in the modern world. They provide the link between the end users and the Internet. They are responsible for the IT infrastructure, working to deliver your online experience.

The signals don’t just appear in cables at your apartment or office. A lot of hardware must work 24/7 to shape the information flow, route it, divide and consolidate it. Plus data storage, cybersecurity, and many more features. ISPs took a vast part in shaping the Internet and the way it looks.

As a result, they are the administrators. This comes with great responsibility and certain rights too. ISP manages your online connection, so it can also control it and even access all your data transfers! This sounds like a privacy invasion, but don’t panic. Usually, it makes no sense for your ISPs to invade your privacy. Depending on local regulations, it might also be illegal without a proper warrant. Still, many people are concerned about that and, for a range of reasons, wish to hide their actions from the ISP. A VPN is the tool of choice here.

Does VPN stop ISP tracking?

A VPN constructs a virtual tunnel from your device to your provider’s remote server. It does not exist physically, like an exclusive cable for you. It is a logical network architecture.

Your data packets get encapsulated by a VPN networking protocol and protected with an encryption algorithm. It’s impossible for any third party to freely access this data. That applies to your household members, nearby hackers, government, and ISP. This technique of VPN does prevent ISP tracking.

The online tracking itself is linking someone’s online activity to him/her as a person. With VPN, your IP is altered, which also impedes spying on you. But does VPN hide from ISP? Not exactly. If you signed an agreement with the ISP, then he obviously knows your basic personal information, including your physical address.

Can ISP see VPN?

Does my ISP know I use a VPN? Can the ISP ‘see’ VPN usage? Well, the answer is: it can learn it with some effort. Your data packets don’t have any direct information, announcing ‘VPN ON/OFF. However, ISP can track VPN down by several clues:

  1. Encryption of 100% of traffic. It’s quite common to cipher online data. That’s the function of the popular HTTPS protocol. But it rarely encrypts everything because it does slow the connection down. If every piece of information from a device is encrypted, then it’s probably using a VPN.
  2. All packets are destined to the same IP. If monitoring over some time shows that all your data is routed to the same address, then a conclusion might be: it’s your VPN provider.
  3. The IP you’re connecting with belongs to a known VPN server. A lot of information about IP address allocation is public. Your ISP can see through your VPN some unencrypted information, like the IP address you’re connecting with. If it manages to find out that this IP was allocated to a VPN-running company, then it’s obvious what your deal is. 

VPNs do hide from ISP, but it mostly applies to the contents of your Web browsing, not the fact that you’re using a VPN. Some VPNs use obfuscation techniques to add another layer of encryption, which disguises VPN as regular traffic. Others periodically change their servers so that they can’t be identified as belonging to a known VPN service. Some VPNs called residential VPNs use real household IP addresses, not dedicated standalone servers that are easy to track and block. 

What does my ISP see when I use VPN?

The important question is actually: can the ISP see the sites I visit with VPN? This is what privacy-sensitive users wish to hide. But VPN encrypts all of your data traffic, so the Web contents you view are kept secret.

What ISP does see is metadata of the protocols applied, like the IP of your VPN provider. These are mostly not very useful for tracking you down. But there is a case when your privacy might be endangered despite using a VPN: DNS leak.

DNS queries are used to determine the IP addresses of the online services that your browser requests. Sometimes even with a VPN on, they are passed directly into ISP’s DNS server, thus revealing what websites you visit! This is what a DNS leak is, because it ‘spills’ your private information into unauthorized hands. A well-designed VPN service prevents this by directing the DNS requests into the VPN provider’s server with the rest of the traffic.

If I use a VPN, can my ISP track what I download?

This could sound like a separate matter, so it’s better to clarify it. File downloads are a part of your browsing, so they do get protected with the VPN. Another matter, quite different from regular downloads, is: does VPN hide torrenting from ISP? The answer is yes, almost.

Sharing files via torrent clients is part of data traffic, which gets protected by a VPN. But a cybersecurity expert might use the specific behavior of the P2P protocols used here. Recognizing the usage of torrents is possible, but it requires professional packet inspection. It’s very unlikely for your ISP to pay its experts to check if you’re using torrenting software. Even then, it’s impossible to pinpoint exactly what you are downloading. It could be perfectly legal; for example, many open source projects are shared in the community via torrents.

ISP blocking VPN

The ISP can track the mere usage of a VPN, and it can also impose a restriction on it. Can ISP block VPN? The answer is yes, but… what for?

ISP makes a profit by delivering you an effective connection. If you don’t do anything illegal or violate the agreement, the ISP doesn’t care if you use a VPN. Moreover, in the post-COVID-19 world, VPNs are in high demand. Multiple entrepreneurs were able to withstand the pandemic thanks to safe VPN tunnels established from home offices to the company server. This enabled the work to be done without jeopardizing confidential corporate data. So blocking VPN is not only troublesome, but it is also bad for business.

There are always some exceptions, however. Some countries ban VPN usage or regulate it strictly. Governments might demand that ISPs execute such regulations. It applies mostly in the areas of the world where freedom of speech is limited, like China, Iran, North Korea, and Russia. When abroad, be careful not to unintentionally break the law!

VPN doesn’t have to collide with the ISP’s interest at all. Under most countries’ jurisdictions, there is no legal reason for ISP to discourage you to use VPN as much as you like. Does the ISP actually tamper with your private data is a tough question. It depends on their inside policy, the agreement you’ve signed, and if your data gets sold to third parties. VPN is the right choice for anyone concerned about their privacy. Subscribe to a reliable VPN service and be safe!

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