[tor-talk] ISP CenturyLink Blocking Tor?

[Matthew Finkel]

On Sun, Feb 01, 2015 at 04:14:26PM +0000, nathaniel at moltennetworks.co.uk wrote:
> I have been at a close friend's house recently and his provider is
> CenturyLink (at home I use TimeWarner Cable). I tried to download
> Tor Tails (over BitTorrent) and the Internet literally dropped so I
> closed BitTorrrent, afterwards I launched the Tor Browser Bundle and
> then my computer was disconnected from the router and couldn't
> reconnect and no one at the house could access the Internet, we had
> to reboot the router to fix the issue. I then enabled Pluggable
> Transports (meet-google or something like that) and now I'm able to
> connect to Tor without any issues. This really concerns me as I was
> able to repeat the crash by launching Tor Browser Bundle and crash
> the router again.
> 

Wow. That is quite coincidence. Can you ask your friend to contact
CenturyLink and ask them why this happened. It appears no one has
experienced this or, at least, no one updated the Good/Bad ISP wiki
page with this[0].

You probably chose the meek-google pluggable transport[1]. Basically,
it takes advantage of the fact that someone can run a webserver on
Google's infrastructure (using AppEngine) such that when you establish
a HTTPS session with the webserver, your ISP only see the connection
to Google's servers and not the specific server you're connecting to;
the specific webserver (meek) is defined within the encrypted portion.
When Google receives the connection, it correctly passes the
connection to the meek webserver. From there, the webserver then sends
your connection to a Tor Bridge, which is your first hop into the Tor
network. It's a very cool idea and it seems to work very well. The
current Tor Browser also supports connecting to a meek instance running
on Amazon's EC2 infrastructure and on Microsoft's Azure infrastructure.

[0] https://trac.torproject.org/projects/tor/wiki/doc/GoodBadISPs
[1] https://trac.torproject.org/projects/tor/wiki/doc/meek#Overview

> This worries me as I can see a direct link (Launch Tor Browsre
> Bundle without Pluggable Transports) and (Router and Internet
> require Reboot). Could this be a form of censorship within the
> United States?
> 

Sounds like it. It would be great if someone directly asks CenturyLink
about this.
> I will be returning home today but this is really worrying me as it
> could be a form of censorship within the United States.
> 
> Does anyone have any ideas or thoughts about this?

It's interesting that resetting the modem allowed you to access the
internet again. I wonder if the internet connection block you
experienced was based on the modem's IP address, and when you reset
the modem it was given a new dynamic IP address - hence bypassing the
block. This reminds me a little of the way China handles connections[2],
but it's still a little early to make a serious comparison.

The more information we can get about this, the better.

[2] https://blog.torproject.org/blog/closer-look-great-firewall-china


Also, as a general aside, please remember that trying to run a
bittorrent client over Tor is a bad idea[3] (the first half is the
relevant portion). I'm not sure if this was the intention, but just a
a friendly reminder :)

[3] https://blog.torproject.org/blog/bittorrent-over-tor-isnt-good-idea