[tor-bugs] #15516 [Core Tor/Tor]: Consider rate-limiting INTRODUCE2 cells when under load

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#15516: Consider rate-limiting INTRODUCE2 cells when under load
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 Reporter:  special                              |          Owner:  dgoulet
     Type:  enhancement                          |         Status:  closed
 Priority:  Medium                               |      Milestone:  Tor:
                                                 |  unspecified
Component:  Core Tor/Tor                         |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  tor-dos, tor-hs, network-team-       |  implemented
  roadmap-july, nickm-merge                      |  Actual Points:
Parent ID:  #29999                               |         Points:  10
 Reviewer:  asn                                  |        Sponsor:
                                                 |  Sponsor27-must
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Comment (by cypherpunks):

 I have deep concerns about this. It may not help against DoS at all, and
 NACKing in reply rather than dropping may make it worse. Although there
 are many of of them, the bandwidth consumed by INTRODUCE2 cells is not the
 main problem. The best defense in practice would likely be as described in
 https://lists.torproject.org/pipermail/tor-dev/2019-May/013849.html, or
 that, but modified so it's the service that drops them rather than the
 intro point. That would allow current unmodified relays to be used as
 intro points.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/15516#comment:54>
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