[tor-bugs] #24902 [Core Tor/Tor]: Denial of Service mitigation subsystem

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#24902: Denial of Service mitigation subsystem
-------------------------------------------------+-------------------------
 Reporter:  dgoulet                              |          Owner:  dgoulet
     Type:  enhancement                          |         Status:
                                                 |  needs_revision
 Priority:  Very High                            |      Milestone:  Tor:
                                                 |  0.3.3.x-final
Component:  Core Tor/Tor                         |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  ddos, tor-relay, review-group-30,    |  Actual Points:
  029-backport, 031-backport, 032-backport,      |
  review-group-31, SponsorV                      |
Parent ID:                                       |         Points:
 Reviewer:  arma                                 |        Sponsor:
-------------------------------------------------+-------------------------

Comment (by teor):

 My relay radia4 became unmeasured shortly after I disabled my firewall and
 started relying on the DDoS defences. And then a few hours later, it came
 back up again.

 I've checked that it's reachable on IPv4 and IPv6, and that the remaining
 firewall rules aren't blocking anything (unless the authorities are making
 *lots* of connections).

 Could the authorities (or the bandwidth authority clients) be triggering
 one of the defences?
 Aren't authorities meant to be exempted as relays?
 Perhaps the bandwidth authority clients are building too many circuits?

 (In particular, maatuska, bastet, moria1, and faravahar stopped voting for
 it.)

 https://atlas.torproject.org/#details/C6B3546CC6BCCB649FEC82D348D464554BC6323D
 https://consensus-health.torproject.org/consensus-
 health-2018-02-13-01-00.html#C6B3546CC6BCCB649FEC82D348D464554BC6323D

 It's back up now, so it's not a big deal. But we should watch out for
 missing relay votes during 0.3.3.2-alpha.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/24902#comment:69>
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