> On Feb 24, 2017, at 12:35 PM, Evan Hunt <e...@isc.org> wrote: > > On Fri, Feb 24, 2017 at 02:46:28PM +0000, Edward Lewis wrote: >> The reason I point this out is that the order of records in a section has >> been famously undefined, with the convention of supporting round robin >> (an undocumented feature of the protocol) hanging around, for all of >> eternity. I can see an implementation recommendation note because it >> makes sense, but, if we use the old rule of "for interoperability" I >> don't see specifying the order of records as necessary. > > The order of RR's within an RRset is undefined and needs to remain so, but > can there be constraints on the order of RRsets within a section?
While I would love to say Yes to above, that can not be any stronger than “SHOULD” The old RFC’s are much less prescriptive than modern ones. If we ever do a RFC2181-bis or followup work then this should be one of the topics There are basically two ways to handle it - Prescribe order - Dicate that whole section must be consumed and “ordered” before processing. One corner case that I seen on couple of occasions is CNAME chain out of order, I have no idea how that can happen … > >> I also think that goats have already left the burning barn on this. >> Going forward code might put the DNAME ahead of the CNAME, but if past >> code doesn't, going forward code must account for that. > > It took us a very long time to encounter the first server that did > CNAME-first. Most are going to do DNAME-first because it's simpler to > code that way: it's easier to append to a message than insert something > into the middle. > > IMHO the problem is now big enough to see, but still small enough > to step on by declaring we didn't mean for it to be legal. > I was around the time DNAME was defined, and my recollection was that CNAME after DNAME was so obvious that no-one thought is was needed to specify. >> Not to mention the difficulties in writing so-called clarification >> documents. They aren't all that pleasant... > > Well, that's why I started with an email thread… Thank you for bringing real issue to WG Olafur _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
