At Sat, 29 Jul 2017 14:27:57 +0100, Tony Finch <d...@dotat.at> wrote:
> > - One possible idea of another extended error code: one that indicates > > a type-ANY query is responded with just one type of RRset when there > > can be more. > > Note that it is almost always the case that ANY answers from > non-authoritative servers are a subset of the records :-) > > And it seems difficult for a cache to determine when to use this extended > error code. If the cache was populated by an A query (say) it can't know > if this is a subset of the owner's records or not; if it populated the > cache from an ANY query then the records can expire at different times, so > it would have to keep track of this to know if the extended error becomes > relevant. Good point, I was not thinking about the full path from auth via recursive to stub when I made this comment. As you said it's not straightforward. This could still be possible, e.g., if the authoritative server deliberately returns a single RRset to an ANY query with the extended (error) code and the recursive server caches it with marking the sense of the extended code. But it will introduce additional special case to the recursive server implementation, and the benefit may not be worth the complexity. -- JINMEI, Tatuya _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
