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Date: Tue, 27 May 2008 11:53:26 -0700
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From: JINMEI Tatuya / =?ISO-2022-JP?B?GyRCP0BMQEMjOkgbKEI=?=
	<Jinmei_Tatuya@isc.org>
To: Steve Bertrand <iaccounts@ibctech.ca>
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Cc: freebsd-net@freebsd.org
Subject: Re: IPv6/IPv4 DNS resolver source
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At Mon, 26 May 2008 18:49:35 -0400,
Steve Bertrand <iaccounts@ibctech.ca> wrote:

> Is there anyone here who can advise me where in the source tree I would 
> find the DNS resolver code that performs AAAA/A record lookups, and more 
> specifically, the fallback to A lookup if AAAA fails?

Assuming you're considering getaddrinfo(), see res_queryN() in
lib/libc/net/getaddrinfo.c.

BTW: "fallback" does not really accurately describe the behavior.
When AF_UNPSEC is specified, both AAAA and A queries are issued,
whether or not the AAAA query fails.

---
JINMEI, Tatuya
Internet Systems Consortium, Inc.