Connection timeout, unable to connect

[stevet]

What is the name of the domain?

api ibrinc com

What is the error number?

N/A

What is the error message?

Connection timeout

What is the issue you’re encountering

A client has been unable to connect to our site, starting last week.

What steps have you taken to resolve the issue?

DNS looks good, it lists the Cloudflare IPs.
Telnet to domain port 443 gives connection timeout.
Client reports traceroute and ping fail 100% packet loss.
They have been able to connect to us before last week.

What feature, service or problem is this related to?

I don’t know

What are the steps to reproduce the issue?

I can’t reproduce it. Client can’t reproduce it with another machine on same network.
Development machine can nslookup and see Cloudflare IPs, but telnet to port 443, and wget/curl fail with connection timeout.

My guess is it sounds like a firewall issue on their side, but maybe I’m missing something? Any ideas on what else to try?

[fritex]

@stevet

Connection timeout

May I ask what known troubleshooting steps have you tried already regarding 522 error for your Website?

Community Tip - Fixing Error 522: Connection timed out

Error Try the suggestions in this Community Tip to help you fix Error 522 “ERR CONNECTION TIMED OUT” in Google Chrome or “The connection has timed out” in Firefox. Background A 522 error happens when a TCP connection to the web server could not be established. This typically happens when Cloudflare requests to the origin (your webserver) get blocked. When this happens, you’ll see “ERR_CONNECTION_TIMED_OUT”. [image] Quick Fix Ideas Make sure that you’re not blocking Cloudflare IPs in .hta…

Troubleshooting Cloudflare 5XX errors · Cloudflare Support docs

@stevet

Client reports traceroute and ping fail 100% packet loss.
They have been able to connect to us before last week.

Was anything lately changed on the origin host/server or with firewall?

Does it work fine when Cloudflare is temporary Paused?

• Use the “Pause Cloudflare on Site” option from the Overview tab for your domain at dash.cloudflare.com .
• The link is in the lower right corner of that page.
• Give it five minutes to take effect, then make sure site is working as expected with HTTPS without any error

Is the origin SSL certificate still valid? Is your web server still listening to 443 port?

Are Cloudflare IP allowed to connect?

Cloudflare IP addresses · Cloudflare Fundamentals docs

[stevet]

I’m sorry, I should have said right up front that I didn’t think this was a Cloudflare issue. I still don’t, but I was desperate for ideas.

The 522 connection time out error - to be explicit, that is an error you would get from Cloudflare right? As in HTTP status code 522 with HTML? The client wasn’t able to even connect to the Cloudflare IP addresses. When trying telnet, they were never seeing the “Connected to” part. Curl was also unable to connect. I specifically asked client about what curl was saying, it was not getting 522, but timing out connecting (the TCP/IP part).

My first thought was something with the certificates from Cloudflare, which I checked. They upgraded back in November 2024, so it would have broke then, not now. Realistically processing the certificates happens further along the negotiating process, they weren’t making it to that part.

I was able to connect fine, as were all other clients. Even a machine on the same network as their production machine could connect just fine. This makes me think there was something very weird going on in their network with routing.

Nothing was changed on our server like firewalls/IP/host. I checked the certificates on our web server as well. It had also upgraded in November 2024, and other locations has no issues connecting to us through Cloudflare.

As of 2:13 PM EST yesterday (1/14), they have had no problems connecting.

I wish I knew what changed, I don’t like problems I’m not sure how to trouble-shoot.

Thank you for the suggestions.