Re: [DNSOP] Mandated order of CNAME records in a CNAME chain?

[Viktor Dukhovni <[e-mail]>]

On Thu, Sep 29, 2016 at 09:03:33AM -0400, Robert Edmonds wrote:

> > Very good question but, IMHO, it is thread-stealing (hence changing
> > the subject, and removing thread headers).
> 
> I think there was already a thread on this topic recently on this list
> ("Order of CNAME and A in Authoritative Reply" from August 2015). There
> was some discussion over "adding" versus "appending" and it was pointed
> out that a lot of existing code (e.g., the BSD stub resolver) was
> written using the "add at the end" meaning.

Right you are, and it seems I even participated in that discussion,
though it has entirely faded from memory.  All that said, it seems
to me that no conclusion was arrived at in that 2015 thread.

I'm inclined to conclude (as suggested off-list) that, while it
may be prudent to parse conservatively, and not make ordering
assumptions, in fact less tolerant stub resolvers are sufficiently
common and so one would likely get away with assuming natural
ordering.  So perhaps doing it right is not entirely overkill...

-- 
	Viktor.