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Standard VPNs certainly will be blocked, but there are some that are designed specifically to circumvent this kind of blocking, although they can only circumvent it for a short period of time.

I read a comment where you mentioned that the ISP is able to know when someone is using a VPN partly because the ISP knows that the packets are going to the VPN's server. But then, how is it possible that so many people in China or the UAE use VPNs? In fact, the ISPs in those countries actually block the VPN's websites. If they know that the packets are going to the VPN's server, then why don't they prevent the packets from being sent over there in the first place?

In this excerpt from Answercast #56, I look at the difficulties in using VPN services from countries that want to block these services.

VPN services

It's interesting. My gut reaction to this is that what's really happening is a glorified game of whack-a-mole. So, what it means is that the VPN services are basically changing the IP addresses of their servers on a semi-regular basis.

Many standard VPN services, the ones that don't play this game, they can't be used from those countries. This applies to both VPN services and proxy services.

Jumping servers

There's a big market in... I don't want to say "market"... there's a big organized effort to provide proxy servers to people who are in countries behind these kinds of firewalls.

The way that they do that is provide proxy services, provide VPN services, on a large number of different servers whose IP addresses effectively change. Once these other countries determine that this server is being used as a VPN and they block that server... well, the server side knows that happens so they fire up another server on a different IP address or they move the server to a different IP address. That way, that new IP address is not blocked.

People in those countries can use the server for a while until that country says, "Oh, well here's another VPN service on a new IP address. We'll block that IP address." And then the process starts all over again.

It's a "game"

Like I say, that's why I call it a game of whack-a-mole. It's a game of cat and mouse. It's a game where basically you keep changing IP addresses every time your IP address gets blocked.

People in those countries that are trying to use these services have a really hard problem. They need to be able to know what to connect to and there are various techniques that people are using to get the information about what today's proxy settings are. But by and large, that's what it takes.

VPN's can be blocked

You're absolutely right; a VPN service that is on a specific IP address can absolutely be blocked and typically is blocked. But what happens is that VPN and proxy servers are out there on changing IP addresses; IP addresses that change as soon as they're blocked, giving people that are in those countries an opportunity (at least for awhile, until the IP address gets blocked) to connect out to the rest of the internet.

It's an interesting problem and it's a difficult problem. It's a problem that has both pros and cons to it.

Political arguments

Governments on the inside feel that they have the right to "protect" (so to speak) the people in their countries. On the other hand, political activists and so forth believe strongly that it's important that information be able to flow freely in both directions across those kinds of firewalls.

So, it's like I said, it's an interesting problem. It's a game of cat and mouse. It's definitely not simple.

Ultimately, you're right. Standard VPNs will be blocked, but the ones that are designed specifically to circumvent this kind of blocking really only circumvent it for a short period of time and then the game starts over again.

End of Answercast 56 Back to - Audio Segment

Article C5860 - September 27, 2012 « »

Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

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1 Comment
Don Gilcrease
September 28, 2012 8:46 AM

Ultrasurf is popular with people in firewalled countries. And they now publish UltraVPN. They are apparently blocked in some countries though, because they provide true internet anonymity. Check them out on, and they're free.

Information - not spam.

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