[dnsdist] Many "NS ." requests

[Stephane Bortzmeyer]

My resolver suffers under the many "NS ." requests it receives. I
don't know if they are misconfigurations or deliberate attacks, but I
would like to block/limit them.

The resolver accepts only encrypted connections (I observe the
name/type requests by snooping on the backend) and, unless I'm wrong,
dnsdist does not allow to see the pairs request/client (only the top
requests and the top clients, but separate).

What are the possible solutions?