Hi Ray On Mon, Sep 17, 2018 at 09:47:50AM +0100, Ray Bellis wrote: > On 17/09/2018 08:43, Mukund Sivaraman wrote: > > > 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. > > .... > > > 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. > > This is not true. > > Ondrej demonstrated at the last hackathon that permitting a CNAME > alongside the apex can cause MX-related failures in resolvers that are > not upgraded.
"The suggestion is only to require support in resolvers going forward for CNAME co-existing with other types for now." It is obvious if authoritatives did that today and a RFC 1035 resolver cached a CNAME, it would match the cached CNAME when doing a type lookup in cache. Mukund _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop