approximately 50,000 name servers that are authoritative for .com
(according to the .com zone file from the InterNIC).
No. There are approximately 50,000 unique nameserver hostnames. At least
1/3rd of these, according to the survey I'm running right now, are completely
bogus and simply don't exist.
The survey that I'm running to study penetration of the eDNS roots gives
a best guess of the ACTUAL .COM domains which are resolvable to be somewhere
between 30% and 60% of the zones listed.
We're about 10% of the way through the list right now (started early this
morning) so what I have at this point has statistical significance.
You hear that right folks. About 30% of the nameservers which supposedly
are authoritative for .COM domains are either:
1) Non-existant (they don't resolve to an IP address)
or 3) Don't know what "." is (!)
Now, if it turns out that the number of so-called delegations which aren't
really backed by authority records is also 30% of the listing, then that
means that of the 790,000+ domains in the COM zone, only about 265,000 are
"real", in that they have both a nameserver online AND a proper authority
record on that nameserver.
This is a direct result of NSI accepting applications for domains, and
listing them, without checking for authoritative SOA records before issuing
the records in the COM zone!
I'm apalled at these numbers. In general, DNS is so broken and polluted
right now that anyone who wants to take cheap shots at the eDNS system had
better clean up their own yard first.
The huge majority of eDNS registrars verify SOA and authority records before
allowing the zone to issue. I know that we do here, and I was shocked at
the number of bogus registrations that I had seen over the last few months.
Now that I've actually studied the existing .COM zone, I'm no longer
astonished. What blows me away is the apparent fact that this large of a
percentage of the data out there is absolute trash, and nobody has cleaned
up the yard.
BTW, "entropy" doesn't explain this. 7 out of 8 registrations in COM are
less than 18 months old according to NSI.