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

[Mark Andrews <[e-mail]>]

> At 23:17 +0000 3/29/08, [e-mail] wrote:
> >I'm going to ask this question here too..  are we talking about the DNS
> >or are we talking about an applications use of data published in the DNS?
> 
> I think that this is the important question when it comes to know 
> what to write.
> 
> As far as DNS is concerned, "so what" if there are multiple PTR 
> records, yadda, yadda, yadda.  It's nothing to the protocol.
> 
> I was made aware of the desire for limiting PTRs to 1 per address 
> entry via traceroute.  What name should be printed in the one line 
> traceroute gives a hop?
> 
> In general, that's the application's problem.  Apps that can't handle 
> multiple PTRs are the problem to me.  (Why is is that weakly written 
> apps point fingers at the DNS and blame troubles on DNS-being-DNS?)
> 
> Perhaps this document should tell apps writers what they can 
> accomplish with multiple PTRs.
> -- 
> -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> Edward Lewis                                                [phone]
> NeuStar
> 
> Never confuse activity with progress.  Activity pays more.
> _______________________________________________
> DNSOP mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/dnsop

	Multiple PTR records do not scale.

	Today we have reverse lookups that fail because people
	followed this path and exceeded the 64K DNS message size
	of TCP.

	When people have a 100 thousand virtual domains on a 
	box you just can't have PTR records for all of them.

	Mark
-- 
Mark Andrews, From [e-mail]  Mon Mar 31 12:34:50 2008
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To: Edward Lewis <[e-mail]>
From: Mark Andrews <[e-mail]>
In-reply-to: Your message of "Mon, 31 Mar 2008 13:17:11 EDT."
	<a06240801c416cbfb5028@[10.31.68.58]> 
Date: Tue, 01 Apr 2008 06:34:38 +1100
Cc: IETF DNSOP WG <[e-mail]>, [e-mail],
	Peter Koch <[e-mail]>
Subject: Re: [DNSOP] WGLC: "Considerations for the use of DNS Reverse
	Mapping"
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> At 23:17 +0000 3/29/08, [e-mail] wrote:
> >I'm going to ask this question here too..  are we talking about the DNS
> >or are we talking about an applications use of data published in the DNS?
> 
> I think that this is the important question when it comes to know 
> what to write.
> 
> As far as DNS is concerned, "so what" if there are multiple PTR 
> records, yadda, yadda, yadda.  It's nothing to the protocol.
> 
> I was made aware of the desire for limiting PTRs to 1 per address 
> entry via traceroute.  What name should be printed in the one line 
> traceroute gives a hop?
> 
> In general, that's the application's problem.  Apps that can't handle 
> multiple PTRs are the problem to me.  (Why is is that weakly written 
> apps point fingers at the DNS and blame troubles on DNS-being-DNS?)
> 
> Perhaps this document should tell apps writers what they can 
> accomplish with multiple PTRs.
> -- 
> -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> Edward Lewis                                                [phone]
> NeuStar
> 
> Never confuse activity with progress.  Activity pays more.
> _______________________________________________
> DNSOP mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/dnsop

	Multiple PTR records do not scale.

	Today we have reverse lookups that fail because people
	followed this path and exceeded the 64K DNS message size
	of TCP.

	When people have a 100 thousand virtual domains on a 
	box you just can't have PTR records for all of them.

	Mark
-- 
Mark AndrewsISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: [phone]                 INTERNET: [e-mail]
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, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: [phone]                 INTERNET: [e-mail]
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