[metrics-team] IPv6 votes and consensus synthetic flags

[teor]

> On 12 Dec 2017, at 02:09, Iain Learmonth <irl at torproject.org> wrote:
> 
> Hi,
> 
>> On 08/12/17 01:29, teor wrote:
>> This is what actually happens in Tor in the consensus case:
>> 
>> Announced | Reachable | Consistent | Votes           | Consensus
>> ----------+-----------+------------+-----------------+----------------
>> No        | -         | -          | -               | -
>> Yes       | No        | -          | UnreachableIPv6 | UnreachableIPv6
>> Yes       | Yes       | No         | ReachableIPv6   | NoIPv6Consensus
>> Yes       | Yes       | Yes        | ReachableIPv6   | ReachableIPv6
> 
> Ok, so for relay search we have the descriptors and the consensus but
> not the votes.
> 
> We can implement ReachableIPv6 and UnreachableIPv6. I don't think that
> we can implement NoIPv6Consensus though, and in some cases
> NoIPv6Consensus would show on Relay Search as UnreachableIPv6. As this
> is an edge case, does this sound OK?

Yes, that's fine.
We expect this to be very rare.
And being able to diagnose using consensus-health is enough.
(We can do this with the current consensus-health by looking for
ReachableIPv6 in the vote but not in the consensus.)

> If so, I'll move ahead with #24388 and rename IPv6 ORPort to
> ReachableIPv6 to bring it into convergence.

Thanks!

T