Consider including fallback directory mirrors with multiple IP addresses
arma describes the advantages of hard-coding bootstrap IP addresses that aren't in the consensus:
https://lists.torproject.org/pipermail/tor-dev/2016-March/010588.html
I think we could do this with fallback directory mirrors, to increase the chances of Tor bootstrapping successfully in these environments.
With two authority attempts in 0.2.7, it's roughly 47% (2/9 + 2/8).
We already have the same or greater probability of bootstrap success with fallbacks and authorities and an increased number of attempts. But it would be nice to use this trick for about 10% of fallbacks.
This will require changes to the fallback selection script and the whitelist format.