It would also be nice if the relay, itself, performed self-checks of
this connectivity and printed a warning log if some failure-threshold is
reached (and possibly disabling the IPv6 ORPort). But, in reality, this
is a hack
Relays already check that their IPv4 ORPorts are working.
Doing reachability checks for relay IPv6 ORPorts is a bit more
complicated, because we have to teach relays to extend over IPv6 first.
Here's the master ticket:
And if relays use authority IPv6 ORPorts to upload descriptors, they
will get connectivity checks for free:
T