Re: TCP connections to DJBDNS

(* Reply-to set to avoid auto spammers *)

Dean Anderson wrote:

> AXFRdns just does AXFR transfers.

axfrdns supports TCP DNS queries, and therefore does for TCP what tinydns
does for UDP.  Additionally, it provides support for AXFR transfers.

> TCP can also be used for all queries, 
> including ordinary lookups.  So if the authority server doesn't listen 
> on TCP/53, it doesn't support TCP DNS.

Ergo, if you're running a djbdns authorative server, you must run axfrdns
if you want to support TCP DNS queries, *regardless* of whether you want
to support AXFR/zone transfers or not.  This talk of patching tinydns to
support TCP queries strikes me as strange, since there's always been a
mechanism within djbdns to support that.  The fact that it's a separate
program probably stems from the use of tcpserver & cdb to provide AXFR
ACLs, and the dominance of UDP lookups (tcpserver will fork axfrdns for
each incoming connection). 
 
> Digression: For some reason that I can't explain, there is a
> misconception that TCP is only used for AXFR.

Likewise with axfrdns.  The name and the documentation at
<http://cr.yp.to/djbdns/axfrdns.html> doesn't help (it mentions almost
incidentally "It also responds to normal client queries, such as SOA
queries, ...")

-- 
Regards,
  Daryl Tester

"Oh Christmas tree, oh Christmas tree!  From hell's heart I stab at thee."
  -- A very Kaaahn! Christmas