On Fri, May 22, 2020 at 10:55:34AM +1000, George Michaelson wrote: > My Colleague George Kuo asked me for definitions of public DNS > service. not "public DNS" but the trigram "public DNS service"
Is there room for this bike: 1) Policy: A "public DNS service" is a full DNS speaker outside of the end user's network and control. I.e., non-local recursion crosses one or more policy barriers---local network, carrier, state and international---with implications for integrity, resolution security, and privacy. For some enterprises, recursion against 'public DNS services' creates an audit criticism. A poorly selected public resolver may import censorship. Or a well selected resolver may evade (older) regional media controls by suggesting false locality to a media server, for those services unwilling to impose policy regional controls in their TCP multiplex. Given these explicit choices and surprise outcomes, "crossing policy barriers" is a fair partial description. 2) Latent RRsets requiring protocol changes. Public DNS servers are the most distant commercially viable DNS iterator from the end user. Resolvers mitigate distance-induced latency via anycasting and robust provisioning. Suboptimal RRset selections required fundamental protocol changes---e.g., exposing local octets to the iterative layer---accommodate what remains. (And hats off to the Tor exit nodes offering on-exit recursion, and injecting RFC 1918 addresses into the ECS payload.) "Distant" is a fair description. Users pay for this distance, in either latency, privacy, or protocol changes. 3) "Free with footnotes". No good deed goes unmonetized. Users should understand the trade offs in selecting a non-local resolver. The term "public" obscures stake holder interests. I suggest: "distant resolver outside of the user's policy oversight". -- David Dagon da...@sudo.sh D970 6D9E E500 E877 B1E3 D3F8 5937 48DC 0FDC E717 _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop