Re: Comcast residential DNS contact

[Doug Barton <dougb () dougbarton us>]

On 12/3/14 10:07 AM, Grant Ridder wrote:
> Did more digging and found the RFC regarding ANY queries:
>
> 3.2.3 - * 255 A request for all records
> https://www.ietf.org/rfc/rfc1035.txt

When listing URLs for RFCs it's better to use the tools site, as it 
gives a much better experience:

https://tools.ietf.org/html/rfc1035

Meanwhile, the text is correct, but what you're missing is the nuance of 
authoritative vs. recursive. If you send an ANY query to an 
authoritative server it is naturally going to send you all of the 
related records, since it has them all.

A recursive (or iterative if you prefer) server only has what it has in 
the cache, but it will send you "all records" that it has. What this 
does not imply is that the recursive server will go out and do its own 
ANY query for the RR you're asking about, unless there is nothing in the 
cache to start with.

There are any number of explanations for why some of the recursive 
servers you're querying have more records than others. None of them are 
bugs. :)

> However Wikipedia (http://en.wikipedia.org/wiki/List_of_DNS_record_types)
> lists this as a request for "All cached records" instead of "A request for
> all records" per the RFC.

Wikipedia is good for a lot of things, but standards work is not one of 
them. :)  The text above is a good example of why.

Doug