BIND 9 AAAA record problems

[phn at icke-reklam.ipsec.nu]

JINMEI Tatuya / =1B$B?@L at C#:H=1B(B <jinmei at isl.rdc.toshiba.co.jp> wrote:
>>>>>> On Mon, 28 Jun 2004 14:55:32 +0000,=20
>>>>>> "Todd T. Fries" <todd at fries.net> said:

>> Why is it a bad thing to start out with AAAA?  Proper getaddrinfo()
>> implementations should query first an AAAA then an A record for names,
>> so that applications can then connect to whatever is appropriate.

>> It is all part of a `seamless' transition to v6 that has started, albi=
et
>> slowly.

>> For whatever it is worth, the libc in OpenBSD behaves this way, and I
>> quite am pleased that it does.

>> It's not a bug, it's a feature ;-)

> In general and in theory, I agree.  But we should also note some
> practical issues in the real world.  To name a few:

> - there are some misbehaving authoritative servers against AAAA
>   queries.  See draft-ietf-dnsop-bad-dns-res-02.txt for more details.

> - I've noticed some applications do not implement the proper fallback
>   mechanisms from IPv6 to IPv4.  Some do not fall back to A queries
>   when AAAA queries fail (with "NONAME").  Some do not try to connect
>   the IPv4 addresses when the attempt to connect to the IPv6 addresses
>   fails.  I see mozilla/firefox show this behavior with its internal
>   resolver routines.

This might be an area where a configurable resolver would be of
value, when an app asks for AAAA the resolver could be
configured to respond "NXDOMAIN" without even asking a nameserver.


> 					JINMEI, Tatuya
> 					Communication Platform Lab.
> 					Corporate R&D Center, Toshiba Corp.
> 					jinmei at isl.rdc.toshiba.co.jp


--=20
Peter H=E5kanson        =20
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