We saw similar a few months ago over a period with our customers transiting Chicago through Lumen.  We found a Cloudflare maintenance was going on at the time, but it seems something went wrong between them and Lumen.  We  could not ping Cloudflare DNS such as 1.1.1.1 or reach other Cloudflare sites over that period.  We had to disable our Lumen link through Chicago to recover.  We never established whose fault it was.

 

-Ian

 

From: NANOG <nanog-bounces+iflanders=springnet.net@nanog.org> on behalf of Landy Bible <landy@ljb2of3.net>
Date: Tuesday, January 28, 2025 at 7:19 PM
To: Mel Beckman <mel@beckman.org>
Cc: nanog@nanog.org <nanog@nanog.org>
Subject: Re: Issues connecting to Cloudflare over IPv4 in Nashville

I don't have them handy on my phone, but luckily the issue had resolved itself by the time I got up Saturday morning, so no need to dig further.

 

On Sun, Jan 26, 2025, 15:08 Mel Beckman <mel@beckman.org> wrote:

Do you have some example trace routes?

 -mel

> On Jan 26, 2025, at 12:10 PM, Landy Bible <landy@ljb2of3.net> wrote:
>
> A client reported issues connecting to various websites this evening
> and I've narrowed it down to cloudflare hosted sites specifically on
> ipv4. My traceroutes go through my upstream all the way to Comcast in
> Nashville where they die.
>
> IPv6 cloudflare addresses work just fine, but several v4 addresses I
> tested fail.
>
> Is anybody else seeing similar issues, or anybody from cloudflare here
> able to help me troubleshoot?
>
> Thanks!
> Landy

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