On Wed, 21 Jan 2015 09:30:44 +0000, Ray Bellis wrote: > >> i realize that "no" votes aren't counted. but that's going to be my input if >> any document along the lines of adding persistence to tcp/53 is adopted by >> the WG. so, for full disclosure, i wanted to weigh in at this stage. > >TCP/53 is already persistent, it just happens most clients don't take >advantage of that feature. > >The point of my draft is to permit signalling that the current >connection should _not_ be persisted ;-)
I want to restate this, because people often confuse current practice with current specifications: DNS over TCP/53 is *already* persistent. No *protocol* changes are needed. *Implementation* changes, however, are needed: - clients need to not blindly close the connection after one request - clients and servers need to use well known implementation techniques (from HTTP) to get good performance---pipelining, processing requests in parallel, sending replies out-of-order (rfc5966), handling TCP fastopen (newly minited rfc7413). (We've measured and reported the performance differences here before.) Paul Vixie replies: } if they did, [that is: if clients take advange of persitent TCP over port 53] } then those initiators would either be a DoS from the responder's point of view, or a } DoS from other initiators' points of view. we are a prisoner to the reasonable expectations of } the billions of devices that were created in the decades-long era of RFC 1034 section 4.2.2. You're saying TCP is inherently a DoS when used for DNS? I don't get it. Some how the web community tolerates persistent TCP without falling over. And you've suggested DNS-over-HTTP is desirable. Won't that also create any DoS problems that stem from TCP? I don't see how DoS is an argument against TCP for DNS. (Unless one assumes hardware and software at the servers is fixed to something like 2004 standards.) What am I missing? -John Heidemann _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
