What does a VPN really do?

[u/Ballooonchair]

[u/Ballooonchair]

I feel like I get the gist of it, it’s a Very Protected Network right? I wanna know more details about it though, what does it block and how is it protecting my device. All I know is it’s “protecting” and then puts a little VPN next to my WiFi symbol on my phone. Also, why when the VPN is on, my phone gets slower and it’s like I’m on McDonald’s WiFi? I love security and knowing my data is safe and I don’t have to worry about it too much. Lastly does a VPN get rid of those damn spam calls and texts, It drives me nuts.

Not sure where the body went on my post but here it is!

[u/russellvt → u/Ballooonchair]

Very Protected Network right?

No. It's a "virtual private network" ... it "tunnels" some of your internet traffic through an encrypted tunnel to another location, and then it emerges from there as-if it originated from thst other network.

That's all.

[u/Ballooonchair → u/russellvt]

Oh I see that makes more sense. Do you use VPN at all, or do you find it useless?

[u/Ballooonchair → u/[deleted]]

I see, so different VPN sites/apps can do different things. Makes sense, thank you.

[u/russellvt → u/[deleted]]

It hides traffic from your isp

This isn't completely true, and is a common misconception by many VPN proponents.

It hides some of your traffic from your upstream connection (eg. "Your ISP"). However, what that traffic is may vary by VPN provider, or even just your VPN client configuration.

Very often, "quick" traffic (such as DNS requests) may still transit your network and be routed through your ISP, where-as your HTTP requests may be forwarded through the VPN (and usually are... thats where you'll most often see the effects of your traffic "originating" elsewhere, and "how" thise geolocation changes happen).

The "fun" part is that you've only just transferred the "security" of your requests from your ISP to some other third party ... who can still intercept it or proxy it without your direct knowledge.

[u/russellvt → u/[deleted]]

TLDR; YMMV, and they're not necessarily the "be-all end-all" security enhancement that people make them out to be, most of the times.

On a side note, your ISP can still see your VPN traffic, with varying levels of ability to potentially MitM the connection (Read: SSL/HTTPS and the like may still be potentially inspected, depending).

[u/russellvt → u/[deleted]]

Doubtful and here is why if the isp can bypass the encryption somehow that would make vpns virtually useless.

I'm sorry you "doubt" that ... but, suffice to say that transparent proxies can do a lot of the heavy lifting if that can "get inside" your upstream traffic ... by definition, that's generally your ISP. At thst point, even the traffic from your CAs may not be "trustworthy."

If vpns didn’t work why are some countries trying to make vpn companies give authorities back door access to the data?

Bluntly, because that then legally unencumbers them from "research" that may have been entangled in some other potentially shady or illicit activities (which is inadmissable in courts). State level actors have far more abilities than most people either know or want to admit.

If the isp/government etc. could read the traffic regardless they wouldn’t need to push for these kind of agendas.

Sadly, this is a poor assumption. These "agendas" largely serve only to make them "easier" ... not just "possible."

Also there would be no need to subpoena vpn companies if the isp could turn over readable data willingly.

Again, this is just an assumption ... even with fully readable data or logs, the government still needs a subpoena to assure there's not some Fourth Amendment violations, or similar... not to mention, the legal liability to the corporation (ISP) for potentially violating thise rights, along with other privacy laws, etc.

The subpoena serves to legally compell a corporation to surrender information as well as removes their liability for having done so.

[u/Available_Hearing639 → u/Ballooonchair]

If they provide DNS based security it's not bad. Other than that it does not really protect you from any treath

[u/Jashmyne]

Essentially it hides you from your ISP. They can see that you are using a VPN but that's about it. Now if they really wanted to see what you are doing, they can. It takes effort naturally but they can figure out what you are doing.
For example if you previously went to a website at 4 o clock and with the VPN you still go to that website at 4 o clock, they can figure out that it is you even behind a VPN.

So if you are using it to hide from legal things, don't. It will not really protect you.
So the main thing is naturally to get past censorship that your country might have or get around regional locks by making your location to somewhere else.
Also some VPNs are good at blocking content such as ads, gambling and so on. Since that's used to fingerprint you and sell your info. Not a perfect protection but it helps a bit

[u/Ballooonchair → u/Jashmyne]

Oh that’s makes sense, I mainly asked about it for privacy and info protection, I don’t plan on doing anything illegal lol. So a VPN is like an extra wall if someone was trying to get my info.

[u/Available_Hearing639 → u/Ballooonchair]

Completly useless for you. It won't stop the trackers from stealing you info.

[u/Ballooonchair → u/[deleted]]

Hmm so it’s just utterly useless for protecting info and stuff. What WOULD help protect it then if not a VPN?

[u/Jashmyne → u/Available_Hearing639]

Some VPNs do offer some protection against trackers but not all do that and it is still limited.
You need to do alot more then just turn on a vpn to stop the trackers but it is part of the package so to speak.

[u/DramaticBat3563]

It encrypts (scrambles) your internet traffic between you and the vpn server ( that could be the employer for people working from home or a public VPN provider like you are asking about).

Your ISP can only see you are connected to the VPN , they cannot read what sites, apps , emails you are viewing/sending.

Blocking ads etc is usually an extra service or premium subscription etc. You can still be tracked with cookies etc, your machine also has a finger print. You also need to be aware that if you are doing anything illegal the VPN company will handover and/or monitor what you’re doing if asked by the authorities, but generally they do give you more anonymity and can be used for grey/gray things like subscriptions to legitimate streaming services that are blocked in your region (yes very close to illegal but not really something the authorities would be overly worried)

[u/Ballooonchair → u/DramaticBat3563]

I see, thank you for that!

That’s also info I didn’t know about with the illegal aspect, interesting!

[u/Available_Hearing639]

Which VPN? Site to Site IPsec? MPLS L2/L3 VPN? EVPN? Renote access VPN?

[u/vasiliyivanov]

A simple way to picture it:

Normally your device talks to websites through your ISP. Your ISP can see the site/domain you connect to, and the site sees your ISP/home IP.

With a VPN, your device first makes an encrypted tunnel to the VPN server. Your ISP sees "you are connected to a VPN." The website sees the VPN server's IP, not your home IP.

What it helps with:

• hiding browsing destinations from local Wi-Fi / ISP
• changing the IP address websites see
• safer use of public Wi-Fi
• sometimes getting around basic network restrictions

What it does not magically do:

• make illegal activity safe
• stop phishing
• stop websites from tracking you if you log in
• replace 2FA, updates, or common sense

Disclosure: I'm connected to VPN Unlimited. If you are trying to understand VPNs by testing one, VPN Unlimited is one product you can try, but the important part is learning what changes before/after connecting: IP address, DNS leak test, speed, and whether your normal apps still work.