[dns-operations] Registrar for .net and .com fails to accept an NS in .edu

[Florian Weimer]

* Grant Taylor:

> On 12/04/2018 06:18 PM, John W.O'Brien wrote:
>> My .edu registrar has informed me that they are unable to register
>> server names with greater than three labels. So... The saga
>> continues?
>
> Do you (or anybody) have any idea where this limitation comes from?

My guess it dates back to the days when WHOIS.INTERNIC.NET performed
prefix matching by default and returned a bunch of name servers whose
names started with “EXAMPLE.COM.” when you queried it for “EXAMPLE.COM”.
If my guess is correct, the registrar in question just wanted to avoid
the hassle that came from customers exploiting that quirk.  For almost
all customers, this trick doesn't work if you restrict them to three
labels (and chances are the registrar in question did not serve the
eight or so customers where it still would have worked).

Here's a more colorful description of the historic behavior:

  <https://slacksite.com/humour/whois.html>

Thanks,
Florian