Mailing List Archive: IPv6 connectivity to mx[1-4].smtp.goog.

IPv6 connectivity to mx[1-4].smtp.goog.

Feb 27, 2024, 5:02 AM

Post #1 of 4 (207 views)

Hi,

At https://internet.nl we're seeing IPv6 connection issues on TCP port
25 (SMTP) to mx[1-4].smtp.goog.

Either 100% DROP (so no TCP connection) or ? failure to setup connection.

Further testing seems to confirm the problem is bigger and on Google's side.

So, this fails:

echo 'quit' | nc -6 -w 3 mx1.smtp.goog. 25

and this works:

echo 'quit' | nc -4 -w 3 mx1.smtp.goog. 25

(on MacOS use -G instead of -w)

Is anyone else seeing this? Any idea what is causing this?

--
Marco

RE: IPv6 connectivity to mx[1-4].smtp.goog. [ In reply to ]

nanog at nanog

Feb 27, 2024, 7:22 AM

Post #2 of 4 (205 views)

Permalink

We are seeing the same, but seems like it's mostly affecting delivery for broadcom.com, and a few other smaller domains. However, connectivity to the MX listed by gmail.com (and most other domains using GSuite, etc) are working fine over IPv6.

You may also want to ask the mailop list.

--
Alex Brotman
Sr. Engineer, Anti-Abuse & Messaging Policy
Comcast

> -----Original Message-----
> From: NANOG <nanog-bounces+alex_brotman=comcast.com@nanog.org>
> On Behalf Of Marco Davids (Private) via NANOG
> Sent: Tuesday, February 27, 2024 8:03 AM
> To: nanog@nanog.org
> Subject: IPv6 connectivity to mx[1-4].smtp.goog.
>
> Hi,
>
> At
> https://urldefense.com/v3/__https://internet.nl__;!!CQl3mcHX2A!Dc9AZo4F
> nrpVmuo3Ehg5iQUAd4uTAsCdz9MWYKJqFWyWK7_XnaDnWN3_DkOAVq2e5
> CXVOb2triASeebvdg$ we're seeing IPv6 connection issues on TCP port
> 25 (SMTP) to mx[1-4].smtp.goog.
>
> Either 100% DROP (so no TCP connection) or ? failure to setup connection.
>
> Further testing seems to confirm the problem is bigger and on Google's side.
>
> So, this fails:
>
> echo 'quit' | nc -6 -w 3 mx1.smtp.goog. 25
>
> and this works:
>
> echo 'quit' | nc -4 -w 3 mx1.smtp.goog. 25
>
> (on MacOS use -G instead of -w)
>
> Is anyone else seeing this? Any idea what is causing this?
>
> --
> Marco

Re: IPv6 connectivity to mx[1-4].smtp.goog. [ In reply to ]

nanog at nanog

Feb 27, 2024, 12:03 PM

Post #3 of 4 (204 views)

Permalink

Op 27-02-24 om 16:22 schreef Brotman, Alex:

> We are seeing the same,

Thanks.

> You may also want to ask the mailop list.

I was about to do that, when I noticed that the problem seems solved.

--
????????????????????

Re: IPv6 connectivity to mx[1-4].smtp.goog. [ In reply to ]

morrowc.lists at gmail

Feb 27, 2024, 2:19 PM

Post #4 of 4 (202 views)

Permalink

On Tue, Feb 27, 2024 at 12:03?PM ???????????????????? ???????????????????????? via NANOG
<nanog@nanog.org> wrote:
>
> Op 27-02-24 om 16:22 schreef Brotman, Alex:
>
> > We are seeing the same,
>
> Thanks.
>
> > You may also want to ask the mailop list.
>
>
> I was about to do that, when I noticed that the problem seems solved.

sorry about the noise.