DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 70E9D398305A
MIME-Version: 1.0
References: <CABTKjsz75FkcPzEeKfZLB59O-j42jYXH2SqX1jDd-vxUoQDAmg@mail.gmail.com>
 <97e93adb-4782-40bc-d33c-00c27ed56b74@dronecode.org.uk>
In-Reply-To: <97e93adb-4782-40bc-d33c-00c27ed56b74@dronecode.org.uk>
Date: Fri, 15 May 2020 11:47:01 -0400
Message-ID: <CABTKjszwB9vXZKjKomaiovjGpPV+iK94gA_tazmHfWgKmftVow@mail.gmail.com>
Subject: Re: www.cygwin.com DNS setup
To: Jon Turney <jon.turney@dronecode.org.uk>
From: Chad Kimes via Cygwin <cygwin@cygwin.com>
Reply-To: Chad Kimes <chkimes@github.com>
Cc: The Cygwin Mailing List <cygwin@cygwin.com>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: "Cygwin" <cygwin-bounces@cygwin.com>

Thanks Jon!

I see the change went through and I re-ran my validation script a few times
and I don't see the error anymore, which is awesome.

However, I believe my suggestions have inadvertently broken IPv6
connectivity for www.cygwin.com! The CNAME accounts for both A and AAAA
records, but only an A record was added after the CNAME was removed.

To fix this, can you please suggest that the team add an AAAA record
pointing to 2620:52:3:1:0:246e:9693:128c (the address for
server2.sourceware.org)?

Thanks,
-Chad

On Thu, May 14, 2020 at 12:31 PM Jon Turney <jon.turney@dronecode.org.uk>
wrote:

> On 14/05/2020 16:54, Chad Kimes via Cygwin wrote:
> > Hi all,
> >
> > I'm investigating an issue with GitHub Actions runners having issues
> > connecting to www.cygwin.com:
> > https://github.com/actions/virtual-environments/issues/698
> >
> > I worked with the Azure DNS team and in this comment
> > <
> https://github.com/actions/virtual-environments/issues/698#issuecomment-628284472
> >
> > I
> > detail what we believe to be the likely issue. Summarized:
> >
> > www.cygwin.com is CNAME'd to server2.sourceware.org
> > server2.sourceware.org is an NS server for sourceware.org
> >
> > We believe that the above configuration is triggering a bug in WinDNS
> that
> > is causing intermittent DNS resolution failures. I don't have an ETA for
> > resolution from the Azure DNS team, and internally I'm translating that
> to
> > be on the order of months before we see a fix. In order to resolve this
> > faster for customers, I'm reaching out to see what options we have for
> > updating the DNS records that are triggering this bug.
> >
> > Is there a change you can make to either www.cygwin.com or
> > server2.sourceware.org DNS such that it doesn't have this recursive
> > reference issue? Some options are to replace the CNAME with an A record,
> or
> > to use something like ns2.sourceware.org for the NS record instead of
> > server2.sourceware.org which is being used for cygwin's A record
> reference.
>
> I have drawn the attention of sourceware overseers to this.
>
> They have requested the DNS change you suggest.
>
--
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple