[atlas] management access...?

Hi Gert,

> Better diagnostics at the atlas dashboard would have helped me, too,
> but for cases like "I think I have network by my DNS isn't working" or
> "I think I have network but can't connect to my controllers" errors,
> local data might still be beneficial.

This is reasonable, but it leads to a place where probes *do* run services
that are open to "all". I guess it's possible to redefine "all" to be "my
local network" or "the same /24 or /64 as the probe" or such, but that
adds complexity and I'd be reluctant to go that way.

What we're trying to do is what you describe above -- based on signals
sent by the probe we're trying to give useful clues to the hosts about
what's going on. We can look at the current diagnostics and see if we
already squeeze out as much diagnostics as possible. We also plan to
include IPv6 PMTU problems, broken local resolvers and such in an upcoming
iteration.

Regards,
Robert