RE: [council] Discussion draft on unique, authoritativeroot

[John C Klensin <klensin@jck.com>]

--On Tuesday, 29 May, 2001 05:35 -0400 Peter de Blanc
<pdeblanc@usvi.net> wrote:

> Just one comment, Stuart-  where you say:
> 
> "These groups then seek to persuade ISPs and Internet users to
> replace the pre-stored IP addresses of the standard root
> nameservers with those of their alternative servers."
> 
> They do not "replace", they "add to" (in this case, the 'hints
> file').

Peter,

I think you are confusing the initial list of root servers (the
"hints file") with the _content_ of the root zone.  If one adds
servers to the "hints" list, and some are inconsistent with the
others, which domains the user will "see" becomes a
probabilistic matter, especially since the server chosen (more
or less at random) will immediately cause the "hints" list to be
replaced by its idea of the authoritative list of servers.

In case this isn't clear, suppose my "hints" contain the
existing list of root servers plus additional ones, say "X" and
"Y".  And assume that the root zone file supported by "X"
contains delegation records for an "XXX" TLD with NS records
pointing to NS1.XXX-X.org and NS2.XXX-X.org  and that the one
supported by "Y" contains delegation records for an "XXX" TLD
with NS records pointing to NS1.XXX-Y.org and NS2.XXX-Y.org
(note that the situation with different zones claiming to be a
top level XXX domain already exists -- this is not a made-up
example).  The other name servers listed in this augmented hints
file do not contain delegations for "XXX".

Now the user's software makes a more or less arbitrary choice
about which root server to contact out of those listed in the
hints file.  If it accesses any of the well-known servers, names
in the XXX domain will not resolve (note that there is no
looking back and trying a different root server -- that requires
significant resolver changes and raises other issues associated
with "DNS searching").  If it accesses the proported "X" root
server, XXX will resolve, but only that version of XXX
understood by "X" and its designated servers.  And, if it
accesses the proported "Y" root server, XXX will resolve, but
only that version of XXX understood by "Y" and its designated
servers.  That, of course, implies that "hotteens.XXX" might
point to two entirely different domains depending on which
server is chosen by accident, bringing with it all of the other
problems of multiple, uncoordinated domains.

RFC2826 really means what it says.  To summarize in simple
English:  Anything other than a single, unique, authoritative,
root will inevitably fragment the Internet and result in user
confusion.   Names that can be resolved by one user will not be
resolvable by others or, worse, will be resolved to point to
different sites or subtrees.

regards,
    john