If I run DIG with the ANY option on my domain I cannot see any CNAME records returned when some actually exist. Is this by design?
It depends on the name server software used. Some packages don't even recognize the "ANY" query type.
I just love standards........ :)
It seems that ANY will usually get me all the records except CNAME and PTR. Maybe an HE DNS engineer will chime in and clarify this.
Is there an RFC that dictates how a DNS server will (should) respond to queries?
It makes sense to me that an ANY query would not include CNAMEs or PTRs.
PTR format and response is drastically different. If you're querying for *anything* but in-addr.arpa, there won't be a PTR record.
Standard response for a CNAME is to follow the CNAME chain until you get to a record that includes A or AAAA. If you tried to do an ANY query example.com, which had TXT records, MX, and CNAMEs to real1.com, real2,com, real3,com and put them all into a single response: how do you know which host the TXT and MX records belong to? example.com, real1,com, real2.com, etc?
OK, I can agree on the CNAME and PTR but what about A and AAAA records? Would you expect all of those to show up in an ANY query?