[atlas] DNS issue with Atlas or with the ISP?

On Mon, Sep 09, 2019 at 01:06:48PM +0200,
 Philip Homburg <philip.homburg at ripe.net> wrote 
 a message of 20 lines which said:

> The problem is that for a link local address you need a scope. The
> Atlas measurement code doesn't know how to add one and the addresses
> in /etc/resolv.conf don't have one.

I was, too, surprised that it works but some people tested with dig or
drill (I assume it was on monohomed machines, which is the case of
RIPE Atlas probes) and it worked.

Note that RFC 8106 explicitely authorizes it:

   Note: The addresses for RDNSSes in the RDNSS option MAY be link-local
         addresses.  Such link-local addresses SHOULD be registered in
         the Resolver Repository along with the corresponding link zone
         indices of the links that receive the RDNSS option(s) for them.
         The link-local addresses MAY be represented in the Resolver
         Repository with their link zone indices in the textual format
         for scoped addresses as described in [RFC4007].  When a
         resolver sends a DNS query message to an RDNSS identified by a
         link-local address, it MUST use the corresponding link.