How common is lack of DNS server diversity?

Ergo, I thought that it was determined as best practice that; Name
Servers that were offered up, as references, should be root for that level.
That is, they should be non-recursive.

  I don't remember any IETF BCP making that claim.
  Recursion is a tool. It can be very helpful in some
  environments. In inappropriate hands (stupid/evil)
  it can cause serious damage.

Another thing missing is a further definition of <authoritative>. Some of us
have been working with the following;
<Authoritative servers> ::= <zone authority>|<domain level
>><authoritative resolvers>
<zone authority> ::= Final authority for a zone, non recursive.
<domain level authority> ::= Final authority for a DL, non recursive (ie
a.root-servers.net, gtld-servers.net, etc).
<authoritative resolvers> ::= recursive servers, intended for use by
clients, that claim authority for their specific zones. These include
stub-resolvers.

  Not quite what I'd use but its an interesting approch.
  Seems like there is an overlap between data origination
  and data publication. (well, thats not quite right either...:slight_smile:
  

BTW, I consider RFC2870 antiquated, because it presupposes an architecture
which may be outmoded or becoming outmoded rapidly. Load balancing and
clustering technology makes RFC2870 an unnecessary waste of resources and
can even get you into trouble.

  Well, RFC2870 might just have taken a leaf from your
  book and used "root" as you have indicated. Reading it
  sure gives that impression.

Yes, some of this is from work done on the ORSC roots. Yes, one of the
largest problems we have had to overcome, at ORSC, IFWP, and ICANN/DNSO
discussions, were semantic problems caused by overly simplistic and generic
semantics.
....
This happened
at MSFT, ORSC, and other places that didn't join/agree/submit to
namedroppers.

  Its tough when the various parties can't reach agreement
  on the basics. One would hope that discussions are continuing
  between these parties and agreement on semantics can be reached.

--bill