Hi Martin,

> I may be wrong, but doesn't DNS use TCP if the answer to a query
> exceeds a certain length? 

Yes. If the resolver receives a truncated response (TC bit set) it is supposed 
to
re-do the query via TCP.

You are out of luck if your resolver thinks:
 'What the hell is a TC bit?! I'll just try to parse the
  response and pretend that there was no TC bit set. Harr harr..'


This works (somewhat) if the response came from BIND:
 $ dig -x 195.141.232.78 +short +ignore @cns1.bluewin.ch |grep -vc '^;;' 
  14

But it fails if dnscache sent the response:
 $ dig -x 195.141.232.78 +short +ignore @fdad:ecad:e0fb:adf0::f00 |grep -vc 
'^;;'
 0

(dnscache does not include a 'stripped down' response:
  http://cr.yp.to/djbdns/notes.html => Truncation)

Regards,
 Adrian

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