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Re: [dnsext] loads of TXT records for fun and profit

"John Levine" <johnl@taugh.com> Sat, 04 May 2013 01:48 UTC

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Date: Sat, 04 May 2013 01:48:25 -0000
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From: John Levine <johnl@taugh.com>
To: dnsext@ietf.org
In-Reply-To: <51843A93.3010109@dougbarton.us>
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Subject: Re: [dnsext] loads of TXT records for fun and profit
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>> No, that section is all about having a single TXT RR whose complete
>> content doesn't fit in 255 characters.  It illustrates how to achieve
>> this within a single RR in zone file format.
>
>... which doesn't prevent people from splitting them across multiple 
>records.

Section 3.1.2 of RFC 4408 forbids an SPF checker from looking at
multiple records at the same name.  Section 3.2 of the current draft
has the same language.  SPF has to forbid multiple records at the same
name, since their semantics are obviously impossible to define.

A single TXT record can, of course, contain any number of strings and
can be arbitrarily long.  See RFC 1035 sec 3.3.14.

Is there some reason it's preferable to guess rather than reading the
spec?

R's,
John

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