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Re: [DNSOP] SRV and HTTP

Mark Andrews <marka@isc.org> Wed, 11 July 2018 03:44 UTC

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From: Mark Andrews <marka@isc.org>
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Date: Wed, 11 Jul 2018 13:43:53 +1000
Cc: Evan Hunt <each@isc.org>, dnsop@ietf.org
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To: John R Levine <johnl@taugh.com>
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Subject: Re: [DNSOP] SRV and HTTP
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> On 11 Jul 2018, at 1:16 pm, John R Levine <johnl@taugh.com> wrote:
> 
>> On Tue, Jul 10, 2018 at 11:08:37PM -0400, John Levine wrote:
>>> There's over 6000 service names defined for SRV.  That's a lot of rrtypes.
>> 
>> But HTTP/HTTPS is the one we have by far the most problems with.
> 
> True, and there have been some proposals for DNS records to return http parameters.
> 
> It's always been my impression that the http crowd believe that the
> overhead of a two DNS lookups is too slow, for some meaning of too slow.

Which is predicated on the recursive server not filling in the additional section.
Recursive servers can and do fill the additional section with SRV (starting with NAPTR
records) then add A, AAAA and TLSA records.  They can lookup missing record before
returning the SRV or NAPTR records (there is code to do that for SRV).  Its easy to
do the same thing for other record types.  

> Regards,
> John Levine, johnl@taugh.com, Taughannock Networks, Trumansburg NY
> Please consider the environment before reading this e-mail. https://jl.ly
> 
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-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742              INTERNET: marka@isc.org

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