Hello!
Your relay Tor1AS20435[1] seems to fail relaying exit traffic according
to our measurements. We ran tests from differnent vantage points and it
was not possible in 10/10 cases to reach https://example.com. Could you
please look into that and resolve the issue on your end?
Our overall runs and results are available on Github.[2] Please let us
know if you have further questions and when the problem is resolved on
your side.
Thanks for running a relay!
Georg
[1]
https://metrics.torproject.org/rs.html#details/AD1639F47D6233E812A67F98F9D7…
[2] https://arthuredelstein.net/exits/
Hi Matt!
Matt Corallo:
> Hey gk@!
>
> I was directed to send a mail with this to you to make you aware of it
> by a random IRC'izen.
Thanks and sorry for the meeting confusion. It should be better from
next week on once we get used to all the new processes in the network
health world. I am CC'ing the network-health list, so others can chime
in as well.
>> I wanted to point folks to some recent work in bitcoin-land that is
>> likely of particular interest to tor folks: we've begun work to
>> consider the asn which announces a given ip block in our peer
>> selection algorithm in order to bolster our sybil-resistance, and have
>> a relatively-efficient file format to be able to ship the global
>> routing table with our binaries (eventually).... if you're interested,
>> check out https://github.com/bitcoin/bitcoin/issues/16599 (and the
>> academic work on Bitcoin sybil resistance at
>> https://erebus-attack.comp.nus.edu.sg/ ).
>> as well as the encoder for said encoding at https://github.com/sipa/asmap
>
> Happy to get the right folks to join Tor-Network-Health meetings or so
> if there's room to collaborate given the highly overlapping problem sets
> here.
Skimming the paper I think Tor has already included a solution to this
problem a while back: It's the "Whitelisting IP addresses"-approach in
VII A. 3) in the paper, which is not a desirable solution for Bitcoin it
seems.
In particular, the Tor client is not considering any node which is
saying "Hey, I am a Tor node!" when it decides to build a path through
the network, but rather only those nodes the directory authorities have
consensus over. They are essentially the ones who get to decide which
relays count as Tor relays for which purpose (like an exit relay) and
which not, and anyone else uses that consensus (i.e. whitelist) for
path-building. In the Tor context there are no "shadow IPs" which the
attacker can flood a victim node with to get traffic re-routed.
Does that make sense? If not, I am happy to see how you think the Erebus
attack is important for the Tor network. (Don't get me wrong. Tor is not
immune to sybil attacks. It just seems to me that the Erebus version is
not one we need to worry about.)
Georg
FYI.
--Roger
----- Forwarded message from Roger Dingledine <arma(a)torproject.org> -----
Date: Wed, 29 Jan 2020 04:11:46 -0500
From: Roger Dingledine <arma(a)torproject.org>
To: dir-auth(a)lists.tpo
Subject: Directory authorities DDoSed by consensus fetches
Hi folks!
I wanted to let you know about an issue that came up over the past
few weeks, and is continuing.
In short, many thousands of places around the internet are fetching
the vanilla consensus document, uncompressed, from the dirport of the
dir auths.
moria and gabelmoo shot up to 400mbit/s sustained, and even that wasn't
enough because they couldn't reliably interact with the other dir auths
(e.g. send or receive votes) at that level of load.
Probably your dir auth is under huge load currently too.
Here's the plan:
(0) If you need to squeeze down your bandwidth use for now, e.g. by
setting a lower BandwidthRate, do it and don't feel bad. The pain will
continue for a while yet, and answering all of the requests is not worth
getting in trouble with your hoster.
(1) If you're into patching your Tor source yourself, here is a very
simple patch that will help you for now:
https://bugs.torproject.org/33029#comment:18
It prioritizes answering other relays and other directory authorities,
when rate limiting is kicking in. This patch won't by itself reduce
your bandwidth load, but it will let you turn down the BandwidthRate
knob while still being a productive useful dir auth.
(2) We'll have a more thorough version of this patch out sometime soon,
in the form of a git branch and eventually a Tor update. Let us know
if the patch in #1 doesn't do it for you and you need us to get to step
#2 quicker.
(3) Longer term, we need to start refusing (some of) these extra
requests. We have found some simple distinguishers that make us think
they are not actual Tor clients, and that mean we can refuse the requests
without that much collateral damage. We still need to think through
exactly how we want to do that though -- and putting some more defenses
in place, in case the requests morph into something else, could be smart
too. The ticket to follow here is
https://bugs.torproject.org/33018
More when we have it,
--Roger
----- End forwarded message -----
Remi Gacogne:
> Hi Georg,
>
> On 1/23/20 4:21 PM, Georg Koppen wrote:
>> Your relay AquaRayTerminus[1] seems to fail relaying exit traffic
>> according to our measurements. We ran tests from different vantage
>> points and it was not possible in 10/10 cases to reach
>> https://example.com. Could you please look into that and resolve the
>> issue on your end?
>>
>> Our overall runs and results are available on Github.[2] Please let us
>> know if you have further questions and when the problem is resolved on
>> your side.
>
> This should be fixed now. We had a DNSSEC validation issue for this
> domain, due to a MTU issue somewhere along the way between the NS for
> example.com and our recursive servers (DNSKEY answers were lost over
> UDP, leading to DNSSEC validation failure).
>
> I would suggest trying with an additional non DNSSEC-signed domain to be
> able to differentiate various kinds of issues, although I completely
> agree that exit nodes should handle DNSSEC-signed domains gracefully.
Yes, that's a good idea and I'll tweak our script accordingly.
> Thank you for running these measurements of the Tor exit nodes!
You are welcome!
Georg
> Best regards,
>
> Remi
>
Hello!
As written in my meeting notes, which I just sent to the tor-project
list[1], we have a tentative weekly meeting time where we'll talk about
work in the network health area (what we did/what we plan to do, issues
that came up during the week etc.).
Starting with February 3 we'll meet Mondays 1900 UTC in #tor-meeting at
OFTC's IRC network.
Everyone is welcome to listen in and contribute!
See you there,
Georg
[1]
https://lists.torproject.org/pipermail/tor-project/2020-January/002677.html
Hello!
Your relay AquaRayTerminus[1] seems to fail relaying exit traffic
according to our measurements. We ran tests from different vantage
points and it was not possible in 10/10 cases to reach
https://example.com. Could you please look into that and resolve the
issue on your end?
Our overall runs and results are available on Github.[2] Please let us
know if you have further questions and when the problem is resolved on
your side.
Thanks for running a relay!
Georg
[1]
https://metrics.torproject.org/rs.html#details/616081EC829593AF4232550DE6FF…
[2] https://arthuredelstein.net/exits/
Hello!
For those of you not subscribed to our tor-project mailing list here is
the exciting news that we will have a kick-off meeting for our new
network health team this Thursday, at 1800 UTC in #tor-meeting2 on IRC
on OFTC's network[1]. Everyone is welcome!
We have started to collect an agenda and noted already existing tickets
for a potential roadmap[2]. If there are more items we should consider,
please add them. Right now we want to make progress on
- a vision and big items to work on in the medium and longer term
- thinking about potential projects for the upcoming Google Summer of Code
- starting our roadmapping for the coming weeks and months
- setting up processes like other teams already have (weekly meetings,
publishing meeting notes etc.)
See you there,
Georg
[1] See: https://www.oftc.net/
[2] https://pad.riseup.net/p/tor-networkhealth-2020.1-keep