I'd
like to raise awareness of the Comcast blocking.
As stated in subject, I believe Comcast blocks all
traffic between its customers and public tor relay nodes.
That is, the blocking is not limited to tor-related
traffic, all other services / ports on the tor relay are
blocked.
Background: I am running
a lightning node, lightning is a layer 2 protocol to
scale Bitcoin. Lightning nodes need to be connected to
each other ideally 24/7. I was contacted by the operator
of another Lightning node, complaining that he cannot
connect to my node. He is Comcast customer, I am not. I
was also running a tor relay on the same public IPv4
address.
I am pretty sure that the blocking is done by
Comcast and is triggered by being in public list of tor
relays. The blocking disappeared after I stopped my tor
relay and restarted my router (thus getting a new external
IPv4 address). After 1 day, I relaunched the tor relay,
and the blocking reappeared a few hours later. It was also
confirmed by the said operator of the lightning node, who
said there were various rounds of blocking tor, customers
complaining and Comcast lifting the block for some time,
only to reinstate the blocking later.
Comcast thus discourages me and similar people from
running tor relays, or at least forces me to run tor in
bridge mode. So this is an insidious attack on tor. Note
that Bitcoin is not particularly relevant, Comcast is
blocking tor nodes, not bitcoin nodes. So even if you hate
Bitcoin, note that the same problem could arise even if
Bitcoin never existed: e.g. a self-hosted web server,
whose owner wants to donate his free capacity to tor by
running tor relay. By doing this, he prevents any Comcast
customers from accessing his web server, and this
consequence is not obvious at all.
Any ideas on how to combat this? I was thinking
about including some false positives in tor relay list.
Imagine including some Google servers' IP addresses -
Comcast customers suddenly cannot connect to Google,
unless Comcast stops this blocking... or simply whitelists
Google. But those false positives sound ugly and a bit
malicious, not sure it is a good idea.
I already wrote about this publicly, and also wrote
a mail to EFF. Hope I am not spamming, I feel this is
quite important issue and am a bit frustrated by the lack
of attention it gets.