[tor-relays] Fast flag - wrong speed in dir-spec.txt?

Roger Dingledine arma at torproject.org
Fri Aug 30 08:31:44 UTC 2019


On Fri, Aug 30, 2019 at 05:52:22PM +1000, teor wrote:
> The default value for AuthDirFastGuarantee is still 100 KB.
>[...]
> 6/9 authorities use measured bandwidth, rather than reported bandwidth.
> So your relay won't get Fast unless it is measured by the bandwidth authorities,
> faster than 100 KB.

Right, it's this last part that's critical here. Directory authorities
that do their own "bandwidth authority" measurements use their bwauth
numbers rather than the self-reported numbers in the relay descriptor,
for deciding whether to assign flags.

If you go to the very bottom of
https://consensus-health.torproject.org/#relayinfo
and put in this relay nickname or fingerprint, you'll see that 4
directory authorities -- the ones not running bandwidth authorities --
look at the self-reported number, and give the relay the Fast flag. But
5 of them, which are running bwauths, use their own numbers, which put
the relay below the threshold. And since 5 is a majority of 9, their
choice wins.

Hope that makes sense,
--Roger



More information about the tor-relays mailing list