Silly DNS question

[Ben Scott]

On Sat, Jan 23, 2010 at 12:25 AM, Brian Chabot <brian at datasquire.net> wrote:
> Toying with a piece of trivia who's origin I no longer recall, I seem to
> recall that some DNS servers will treat an underscore as a dash.

  Yikes!  That's disturbing.  Domain names are supposed to be unique keys.

  I can confirm that ISC BIND 9.x named does *not* do this:

$ dig TXT +short never_use_this.gnhlug.org. @liberty.gnhlug.org.
"Never use this name"
$ dig TXT +short never-use-this.gnhlug.org. @liberty.gnhlug.org.
$

  I can also say that the Comcast DNS resolvers I've got today do not
monkey with the queries:

$ dig TXT +short never_use_this.gnhlug.org.
"Never use this name"
$ dig TXT +short never-use-this.gnhlug.org.
$

> I tried doing a host lookup both ways and indeed the results were identical

  The detective in me has to point out that doesn't necessarily prove
it's Amazon's *DNS* servers doing that.  Their provisioning system
might replace potentially problematic characters with dashes when
creating DNS records.  This distinction is mostly academic, but I
think we're in that territory already.  ;-)

> I don't know if Amazon's web server would agree, but their DNS servers
> seem to think they are the same.

  Well, both http://thingiverse_beta.s3.amazonaws.com/ and
http://thingiverse-beta.s3.amazonaws.com/ respond with XML, but with
different content -- the latter a "not found" sort of result.  I'm not
sure if that's the web server proper, or custom server-side software
running behind it, that's getting confused.

-- Ben