On Tue, Aug 11, 2015 at 03:09:09PM +0100, Ralph Corderoy wrote: > How do we get the desired behaviour clarified so implementers of servers > and clients have a reference when trying to resolve their disagreement? > IMO, the CNAME should precede the A, but that still isn't precise > enough. Some are asking if it's sufficient that all CNAME precede all > A. Which clients that are not recursive resolvers talk directly to authoritative nameservers (not counting "nslookup", "dig", ...)? If an order is to be specified, then it should not only order all applicable CNAME RRs before any records that bear the final anwer, but also order the CNAME records in a chain of CNAMEs, so that the source CNAME precedes the target CNAME: However, it is not clear why the order of records in a non-recursive response needs to be constrained in any way. Surely, recursive resolvers can reorder the records as necessary? -- Viktor.