Pekka Savola;
>>For an authoritative server answering a query, there are
>>"glue", that is, "critical", additional data and all the
>>other additionals are "courtesy". So, please don't invent
>>new terminologies and just say "glue".
> I used this terminology at first, but others have stated that "glue"
> is where the additional data comes from. So just saying "glue" did
> not appear to be sufficient unambiguous.
There are various sources of the additionals, including MX,
as explicitely specified in 1034.
>>For a resolver receiving a response, it is not distinguishable
>>whether A for NS of referral response is "glue" or not.
>
>
> Sorry for confusion -- I'm mostly interested in the _authoritative
> servers_ sending the response packets. They should be able to tell
> rather easily. The resolvers can probably have some checks as well,
> but as you explain, those seem to be quite a bit more complicated..
>
> Obviously, the resolvers receiving a response have a difficulty
> telling what it is..
And the complication affects an authoritative server combined
with a resolver and cache.
>>An authoritative server should add additionals
>>if it is "glue" and only if it is "glue", "authoritative" or
>>cached as "safe".
> But the question now here is, what if the additional data does not fit
> in the packet due to multiple RRsets (just one RRset would fit)? What
> would be the reasonable approach then?
First, add glues only. If data does not fit, set TC.
If data fits, attempt to add useful "authoritative" or "safe"
data unless it causes truncation.
That's all. There is nothing v6 specific except that there may
be glues other than A.
Masataka Ohta
.
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