Re: Comcast residential DNS contact

[Andrew Sullivan <asullivan () dyn com>]

On Wed, Dec 03, 2014 at 10:07:04AM -0800, 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
>
> 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.

Those two turn out to mean the same thing in the way the DNS community
has come to understand the semantics of the * query.

A resolver that has a cache is able to answer the query for * by
consulting its cache.  There is no signal in the DNS that there are
records for other RRTYPEs at the same owner name and class, so the
resolver is in a position to answer the question, and so it does.

Certainly, the authoritative resolver will always give you every
record at that owner name and class in the authoritative zone in the
event you asked that.

Also, you probably want to look at RFC 4592, which considerably
expands the treatment of wildcards in the DNS.

Best regards,

A

-- 
Andrew Sullivan
Dyn, Inc.
asullivan () dyn com
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