Base domain resolution

[Barry Finkel]

J <usenet at linuxnuts.net> wrote, in part:

>For years I've been taught to never put an A record on a base domain
>(domain.tld).  I know that just about every major domain does this
>these days but that doesn't make it right.  I'd like to be able to
>support my losing position with technical answers so I can point out
>the potential and future problems before they come back and bite us on
>the ass (a CYA measure for me since I know I will lose this fight).
>As I recall it, there were a number of technical reasons why one
>should not have the base domain resolve to anything but I'm afraid I
>no longer remember what all the reasons are any more.  A couple cheesy
>ones come to mind:

What about a domain that uses Windows Active Directory?  If the AD
domain is

     example.com

then a query for "A" record for that domain will return the addresses
of all of that domain's Domain Controllers.  I am sure that there are
many domains on the Internet for which this is true.

Of course, if this is the case, then one cannot omit the "www."
prefix for

     www.example.com

as I doubt that any knowledeable site would host a web server on
each Windows DC.
----------------------------------------------------------------------
Barry S. Finkel
Computing and Information Systems Division
Argonne National Laboratory          Phone:    +1 (630) 252-7277
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