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

[Andrew Sullivan <[e-mail]>]

Dear colleagues,

On Tue, Apr 01, 2008 at 10:36:28AM -0400, Edward Lewis wrote:

> Multiple PTR records can be stored in a single PTR RRset.  If a 
> device at an IP address (v4 or v6) has multiple identities with 
> domain names, it would be good to have a PTR for each.  However, this 
> is not always practical.  In some operational situations, an address 
> may have thousands of domain names holding an address record (A or 
> AAAA) with the address as the value.
> 
> 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.
> 
> If an address has just a few corresponding forward map records, it is 
> worth entering them all.  If an address has many, a better strategy 
> is to enter a few as is needed, adding more only when there is an 
> operational request.

I'm inclined to add this text.  I'd like additional expressions of
support (or edits, or whatever) from the WG to confirm my inclination.

Thanks,

A

-- 
Andrew Sullivan
[e-mail]
[phone] x104
http://www.commandprompt.com/
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Date: Tue, 1 Apr 2008 17:36:02 -0400
From: Andrew Sullivan <[e-mail]>
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	Tue, 01 Apr 2008 14:36:41 -0700 (PDT)
Subject: Re: [DNSOP] WGLC: "Considerations for the use of DNS
	Reverse	Mapping"
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Dear colleagues,

On Tue, Apr 01, 2008 at 10:36:28AM -0400, Edward Lewis wrote:

> Multiple PTR records can be stored in a single PTR RRset.  If a 
> device at an IP address (v4 or v6) has multiple identities with 
> domain names, it would be good to have a PTR for each.  However, this 
> is not always practical.  In some operational situations, an address 
> may have thousands of domain names holding an address record (A or 
> AAAA) with the address as the value.
> 
> 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.
> 
> If an address has just a few corresponding forward map records, it is 
> worth entering them all.  If an address has many, a better strategy 
> is to enter a few as is needed, adding more only when there is an 
> operational request.

I'm inclined to add this text.  I'd like additional expressions of
support (or edits, or whatever) from the WG to confirm my inclination.

Thanks,

A

-- 
Andrew Sullivan
[e-mail]
[phone] x104
http://www.commandprompt.com/
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