Re: Facebook

I don't know if they are discarded as poison by DNScache, right off 
hand, and I'm not going to check tonight.

Glueless domains are a bad idea. Don't do it.  Pick a name in the
domain, add it as a NS for that domain and give it an A record. One IP
address can have an unlimited number of A records pointing to it.

Indeed, the .com and .net servers put in the glue.  But the IETF says
not to:

Dan writes in http://cr.yp.to/djbdns/notes.html:

 For referrals to out-of-bailiwick DNS servers, however, RFC 1034 says 
 that glue is unnecessary. RFC 1537 says the same thing. RFC 1912 says 
 the same thing. The comp.protocols.tcp-ip.domains FAQ says that ``you 
 do not need a glue record, and, in fact, adding one is a very bad
 idea.'' (This is an obsolete reference to accidental poisoning; see
 above.) Some DNS server implementations ignore out-of-bailiwick glue by
 default. So the glueless domains espn.tv and disney.corp are following
 the rules---yet neither of them is reachable.

Like Dempsky points out (that was a good call), the .com and .net
probably aren't recognized by the cache to be the same, so their
out-of-baliwick glue is discarded.

NS records and MX records should have addresses instead of names. But we
can't fix that now. (could have been fixed in IPv6, though)

DNS is not the work of the best and the brightess, that's for sure.  
Not only has it been bad, but it isn't getting any better. Its worse.  
One chair of the DNSEXT working group is qualified only as a Database
admin and is educated as a philospher (truth is relative; what is
reality anyway?...good stuff for con-artists, but not very useful for
engineering), no background as an engineer--has virtually no technical
background whatsoever.  The real tragedy is that DNS protocol could have
been re-done for IPV6, but...well, you can probably guess why it wasn't.
Sigh.

'nite, folks.

		--Dean

On Wed, 10 Mar 2010, Matthew Dempsky wrote:

> On Wed, Mar 10, 2010 at 6:02 PM, Michael Loftis <[email protected]> wrote:
> > There are glue records present for all of the facebook.com NSes within the
> > net. and com. zones.
> >
> > There are glue records also present for all of the tfbnw.net NSes within the
> > com. zone.
> 
> dnscache doesn't go to the extra effort of recognizing that the same
> authoritative name servers control both the .com and .net zones.  (To
> my knowledge, no recursive DNS server does, but I could be wrong.)  As
> such, the *.tfbnw.net A records returned for facebook.com's NS records
> and the *.facebook.com A records returned for tfbnw.net's NS records
> are discarded as out-of-bailiwick poison.
> 
> 

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