> ... but is there a good solid techincal reason why multiple roots
> wouldn't work?
The issues concern records that contain textual names -- most importantly
NS and CNAME records.
The putative problem arises when the zone file creator puts a name into an
NS or CNAME record that uses a TLD that is a different version of that TLD
used by the person who consumes that record.
In other words, if I say in an NS record that one of my servers is
foo.blap.web, and I use IOD's version of .web, then if somebody who
uses CORE's version of .web comes along and uses my NS record then they
will end up with a mis-resolution.
Now, does that error cause any problems?
That's the matter in dispute.
I can imagine a contrived situation in which that mis-resolved NS record
points to a machine that is a) running a DNS server that is b) willing to
answer to my domain and thus c) feed bogus responses.
But that's a pretty conjectural sequence of ifs, the end probability being
rather low.
If one is concerned, there is a way to avoid this from happening - one can
simply recognize the fact that there are some legacy TLDs -
.com/.net/.edu/.org and the ccTLDs that will be in all sanely run root
systems. And one can make sure that the NS and CNAME records always refer
to names in those TLDs.
Sure, that causes there to be a residual latent preference for those TLDs.
But that preference over time that will fade as new TLDs become
established to the degree that one can safely NS and CNAME 'em.
This is, to my mind, a far more preferable solution than the bureaucracy
and the clearly failure prone processes of ICANN.
By-the-way, the limit of 13 servers comes from an ancient limit of 512
bytes on the UDP data size used by DNS packets. (With modern IP stacks
with working IP reassembly engines, one ought to be able to get up to 64K
bytes in a single UDP frame - unfortunately not all stacks have been
adequately tested, so a number in the 16K byte range is more common. And
MTU's less than 1500 are fairly rare in the net these days except on some
PPP links where the MTU has been cranked way down.)
--karl--
