[190550] in North American Network Operators' Group
Re: www.RT.com bad dns record
daemon@ATHENA.MIT.EDU (Baldur Norddahl)
Fri Jul 8 05:12:06 2016
X-Original-To: nanog@nanog.org
To: nanog@nanog.org
From: Baldur Norddahl <baldur.norddahl@gmail.com>
Date: Fri, 8 Jul 2016 11:11:59 +0200
In-Reply-To: <20160708023342.GA15545@hezmatt.org>
Errors-To: nanog-bounces@nanog.org
On 2016-07-08 04:33, Matt Palmer wrote:
> On Thu, Jul 07, 2016 at 06:36:23PM -0700, Ca By wrote:
>> On Thursday, July 7, 2016, Spencer Ryan <sryan@arbor.net> wrote:
>>
>>> Dotted-quad notation is completely valid, and works fine.
>>>
>>> https://en.wikipedia.org/wiki/IPv6_address#Presentation
>>>
>>> http://[::ffff:37.48.108.112] loads fine in my browsers.
>> It may be legit on your network, but people generally don't do that.... If
>> they publish a aaaa record, it usually has a legit v6 address in it.
> That is a legit IPv6 address.
No it is not. It is a format intended to be used only within a process
to store IPv4 addresses in a single common data structure for IPv4/IPv6
or for use in a socket API so a combined IPv4/IPv6 interface can be
provided. There is no requirement that other processes understand it.
There is no requirement that IPv4-mapped addressing is not disabled on a
system supporting IPv6 (RFC4291 section 8 security considerations).
From RFC5156:
2.2 <https://tools.ietf.org/html/rfc5156#section-2.2>. IPv4-Mapped
Addresses
::FFFF:0:0/96 are the IPv4-mapped addresses [RFC4291 <https://tools.ietf.org/html/rfc4291>]. Addresses
within this block should not appear on the public Internet.
You can put it in a AAAA record just as you can configure a 10.0.0.0/8
address there, but there can be no expectation that it will do anything
useful outside your own environment.
Regards,
Baldur
