[tor-relays] Relay MIGHTYWANG consensus issues and loss of STABLE flag

[Sebastian Hahn]

Hi Wang,

> On 29. Oct 2021, at 18:10, Mighty Wang <wang at mighty.wang> wrote:
> 
> I have one pretty large relay, MIGHTYWANG which is an IP4/6 guard, dedicated hardware running on a 1Gb line uncontended. It is usually one of the top 5 relays by consensus weight but on the morning of 14th October it lost Guard status on account of losing the stable flag. 
> 
> I checked logs, connectivity and server health - nothing unusual, everything is generally pretty bullet proof in and around the relay and it had been running for well over a year without a reboot - just the very occasional Tor daemon restart following upgrades but no such activity prior to the 14th.
> 
> So next I checked the consensus and I see that around half of the directory authorities seem to be not assigning the stable flag. See attached screenshot showing current consensus.
> 
> The peering to each of those relays seems OK from what I can see (IP4 and IP6) so any idea what gives?
> 
> I've got a MIGHTYWANG sitting here twiddling it's thumbs because have the directory authorities don't want to use it. Bit of a waste.
> 
> I had similar things happen a few years ago with one of my old relays; again no obvious reason, just seemed to be the a random whim of the directory authorities.
> 
> I've noticed a couple of other long term relays are in a similar position - is this some time of attack, deliberate action or just Tor magic? 
> 
> 
> 
> Wang

I operate gabelmoo and your relay seems to be unreachable via IPv6 from here. Here's a traceroute:

traceroute to 2a02:29d0:8008:c0de:bad:beef:: (2a02:29d0:8008:c0de:bad:beef::), 30 hops max, 80 byte packets
 1  informatik.gate.uni-erlangen.de (2001:638:a000:4140::1)  1.966 ms  2.037 ms  2.214 ms
 2  constellation.gate.uni-erlangen.de (2001:638:a000::3341:33)  0.718 ms  0.770 ms  0.831 ms
 3  yamato.gate.uni-erlangen.de (2001:638:a000::3033:30)  0.829 ms  1.122 ms  1.234 ms
 4  * * *
 5  * * *
 6  * * *
 7  ffm-bb1-v6.ip.twelve99.net (2001:2034:1:6b::1)  19.795 ms  19.786 ms  19.779 ms
 8  prs-bb1-v6.ip.twelve99.net (2001:2034:1:be::1)  20.489 ms prs-bb2-v6.ip.twelve99.net (2001:2034:1:c1::1)  20.931 ms prs-bb1-v6.ip.twelve99.net (2001:2034:1:be::1)  20.509 ms
 9  ldn-bb4-v6.ip.twelve99.net (2001:2034:1:7b::1)  19.517 ms ldn-bb1-v6.ip.twelve99.net (2001:2034:1:7a::1)  19.390 ms  19.334 ms
10  * * *
11  vaioni-ic326121-ldn-b2.ip.twelve99-cust.net (2001:2000:3080:937::2)  20.387 ms  19.464 ms  20.446 ms
12  2a02:29d0:0:1:: (2a02:29d0:0:1::)  39.577 ms  39.414 ms  39.363 ms
13  2a02:29d0:3:1003::1 (2a02:29d0:3:1003::1)  20.520 ms  20.514 ms *
14  * * *
15  * * *
16  * * *
17  * * *
18  * * *
19  * * *
20  * * *
21  * * *
22  * * *
23  * * *
24  * * *
25  * * *
26  * * *
27  * * *
28  * * *
29  * * *
30  * * *

Perhaps this helps analyze the problem?

Cheers
Sebastian