IPv6-misconfigurations

[Ca By]

On Mon, Sep 28, 2015 at 6:57 AM, Thomas Schäfer <thomas at cis.uni-muenchen.de>
wrote:

> Hi,
>
> I am observing sometimes very strange ipv6-misconfigurations.
>
> The last two examples are:
>
>
> www.hs-worms.de
>
> LANG=C wget -6 www.hs-worms.de
> converted 'http://www.hs-worms.de' (ANSI_X3.4-1968) -> '
> http://www.hs-worms.de' (UTF-8)
> --2015-09-28 15:07:07--  http://www.hs-worms.de/
> Resolving www.hs-worms.de (www.hs-worms.de)... 2001:4c80:81:a000::1d
> Connecting to www.hs-worms.de (www.hs-worms.de)|2001:4c80:81:a000::1d|:80...
> failed: Connection timed out.
> Retrying.
>
> and
>
> www.df.eu
>
> LANG=C wget -6 www.df.eu
> converted 'http://www.df.eu' (ANSI_X3.4-1968) -> 'http://www.df.eu'
> (UTF-8)
> --2015-09-28 15:06:56--  http://www.df.eu/
> Resolving www.df.eu (www.df.eu)... 2a00:1158:0:100::26
> Connecting to www.df.eu (www.df.eu)|2a00:1158:0:100::26|:80... failed:
> Connection refused.
>
> Both examples have an AAAA-record and so my assumption also IPv6.
>
>
> The webmaster of hs-worms doesn't answer.
>
> The webmaster of df I did not ask yet - he is a "hoster" and should have
> some monitoring tools.
>
>
> My question: Is it right, that all these misconfigurations will fail on
> ISPs using DNS64/NAT64, except the people using 464xlat additionally?
>
>
>
For an IPv6-only device, it will only try IPv6...there is no fall back to
IPv4.

So, the device will only ask for aaaa ever... it will never as for "a"
record

Since a natural "AAAA" exists, the DNS64 will never send back a synthesize
"AAAA"  to the IPv6 only user.

So, for IPv6-only users, they will not have any access to a site with
broken ipv6.

Generally speaking, it is better to have no IPv6 access than broken IPv6.

CB


> If somebody knows the responsible persons...
>
>
> Regards,
> Thomas Schäfer
>
>
>
> --
>
> There’s no place like ::1
>
> Thomas Schäfer (Systemverwaltung)
> Ludwig-Maximilians-Universität
> Centrum für Informations- und Sprachverarbeitung
> Oettingenstraße 67 Raum C109
> 80538 München ☎ +49/89/2180-9706  ℻ +49/89/2180-9701
>
>
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