Mark Andrews <ma...@isc.org> wrote: > In message > <caje_bqckdfhnjdvxw_a6n+w27calo8jeqxwjjfx29rbh1r_...@mail.gmail.com>, > =?UTF-8?B?56We5piO6YGU5ZOJ?= writes: > > > > In my understanding the latest major concern is about the first > > paragraph of Section 2: > > > > When an iterative caching DNS resolver receives a response NXDOMAIN, > > it SHOULD store it in its cache and all names and RRsets at or below > > that node SHOULD then be considered to be unreachable. Subsequent > > queries for such names SHOULD elicit an NXDOMAIN response. > > It is a SHOULD not a MUST. Having a existing cache entry is a reasonable > exception to the SHOULD.
The second SHOULD in the quote above seems to be explicitly saying that those cache entries should be made unreachable, so I think it would be unreasonable to interpret the SHOULD as meaning "don't implement this requirement". (Really, I think if a spec uses words like SHOULD, it ought to include a discussion of when it is reasonable not to implement that requirement and what are the consequences of not doing so.) I think the spec needs to make an explicit distinction between conforming behaviour for names already in the cache and names not in the cache. Tony. -- f.anthony.n.finch <d...@dotat.at> http://dotat.at/ Fisher: Northwesterly 4 or 5, increasing 6 or 7 at times later. Slight becoming moderate, occasionally rough later. Fog patches. Moderate or good, occasionally very poor. _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
