Hi Stephane On Mon, Sep 17, 2018 at 09:14:14AM +0200, Stephane Bortzmeyer wrote: > On Sun, Sep 16, 2018 at 03:26:56PM +0530, > Mukund Sivaraman <m...@mukund.org> wrote > a message of 66 lines which said: > > > Adding resolver support (to resolvers that don't have it, i.e., > > vs. RFC 1035) does not appear to break current DNS, i.e., it can be > > proposed now. > > [Algorithm deleted] > > The difficult thing is not to specify what the new resolvers will have > to do, but to describe what will happen with the current > resolvers. What will happen when "CNAME at apex" will be deployed, > assuming X % of the resolvers will not be upgraded?
I fully realise what you're saying. The suggestion is only to require support in resolvers going forward for CNAME co-existing with other types for now. That should not break any detail of how DNS is used today. Whether CNAME + other types at apex can be used in the future would be an operational decision for that time of the world. Similar things can be said of other proposals. * If SRV for HTTP is brought into use, what about X% of user agents that don't have support for it? * If a new RR type is introduced, what about X% of resolvers that do not support it? Although it changes current DNS protocol, AFAICT there does not seem to be anything badly wrong with allowing CNAME + other types at a node, where the CNAME is considered a fallback when the required type doesn't exist. Repeating what the original post's author Petr said, this seems to be a simpler change than adding other types for similar benefit, esp. when hacks are already necessary to workaround the case of CNAME and other types co-existing that are seen in the DNS. Mukund _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop