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Re: [DNSOP] WGLC: "Considerations for the use of DNS Reverse Mapping"

Samuel Weiler <weiler@watson.org> Fri, 04 April 2008 15:35 UTC

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Date: Fri, 04 Apr 2008 11:27:32 -0400
From: Samuel Weiler <weiler@watson.org>
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Subject: Re: [DNSOP] WGLC: "Considerations for the use of DNS Reverse Mapping"
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I have read this document and have no objection to its publication.

That said, I share Jinmei's concern that the recommendation against 
depending on reverse mapping is too weak in the context of the rest of 
the document.  I'm in favor of much stronger language saying "don't 
depend on reverse mapping being available".

While I appreciate the spirit of the text proposed by Ed Lewis, the 
below paragraph seems a bit confusing:

>> The number of address records in an PTR set before tripping the upper
>> limit on what can fit on even a TCP carried DNS message is
>> approximately 4000 for A RR only and about 2000 for AAAA RR only.

I believe that adding explicit mention of the dangers of too many PTR 
RRs at a name will help emphasize the "you really shouldn't depend on 
reverse mapping", which is a good thing.

-- Sam
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