Timeout during connect (likely firewall problem)

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My domain is: zimtstangl.de & www.zimtstangl.de

I ran this command: I tried to create the certificate via zerossl.com, I do (and did this in the past often), today all my domains were successful in creating a certificate via HTTP verification. But this single domain keeps to get the error when verifiying the temporaray files. The files do exist. They is a redirection set from port 80 to 443. I can access the files but it seems letsencrypt cannot for some reason. What could be the reason why letsencrypt can’t access my server?

In my apache logs I see the request coming to port HTTP 80 (which is redirected to HTTPS 443 (same url):
66.133.109.36 - - [11/May/2019:13:50:25 +0200] “GET /.well-known/acme-challenge/pWTXuX2M-dwlrjkT1h3ok9wkDADOR-HfT-gv75oZr98 HTTP/1.1” 301 671 “-” “Mozilla/5.0 (compatible; Let’s Encrypt validation server; +https://www.letsencrypt.org)”

But in the logfile from HTTPS, letsencrypt does not even try to GET the file.

It produced this output:

Fetching https://www.zimtstangl.de/.well-known/acme-challenge/AS5HW2tGYeAqVEYz9_3oS2WXrD7OYCJgj9v6MEsAcRU : Timeout during connect (likely firewall problem)

Fetching https://zimtstangl.de/.well-known/acme-challenge/pWTXuX2M-dwlrjkT1h3ok9wkDADOR-HfT-gv75oZr98 : Timeout during connect (likely firewall problem)

My web server is (include version): Apache/2.4.29 (Ubuntu)

The operating system my web server runs on is (include version): Ubuntu 18.04

My hosting provider, if applicable, is: Strato

I can login to a root shell on my machine (yes or no, or I don’t know): yes

I’m using a control panel to manage my site (no, or provide the name and version of the control panel): no

The version of my client is (e.g. output of certbot --version or certbot-auto --version if you’re using Certbot): n.a.

Hi @zimt

there is a check of your domain ( https://check-your-website.server-daten.de/?q=zimtstangl.de ):

You have ipv4- and ipv6 - addresses:

Host T IP-Address is auth. ∑ Queries ∑ Timeout
zimtstangl.de A 81.169.244.118 yes 1 0
AAAA 2a01:238:4368:c600:8352:fcee:fb4a:2655 yes
www.zimtstangl.de A 81.169.244.118 yes 1 0
AAAA 2a01:238:4368:c600:8352:fcee:fb4a:2655 yes

But your ipv6 doesn't work.

Domainname Http-Status redirect Sec. G
http://zimtstangl.de/
81.169.244.118 301 https://zimtstangl.de/ 0.010 A
http://www.zimtstangl.de/
81.169.244.118 301 https://www.zimtstangl.de/ 0.013 A
http://zimtstangl.de/
2a01:238:4368:c600:8352:fcee:fb4a:2655 -14 10.030 T
Timeout - The operation has timed out
http://www.zimtstangl.de/
2a01:238:4368:c600:8352:fcee:fb4a:2655 -14 10.020 T
Timeout - The operation has timed out
https://zimtstangl.de/
81.169.244.118 200 0.113 B
https://zimtstangl.de/
2a01:238:4368:c600:8352:fcee:fb4a:2655 -14 10.030 T
Timeout - The operation has timed out
https://www.zimtstangl.de/
81.169.244.118 200 0.156 B
https://www.zimtstangl.de/
2a01:238:4368:c600:8352:fcee:fb4a:2655 -14 10.024 T
Timeout - The operation has timed out
http://zimtstangl.de/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de
81.169.244.118 301 https://zimtstangl.de/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 0.010 A
Visible Content: Moved Permanently The document has moved here . Apache/2.4.29 (Ubuntu) Server at zimtstangl.de Port 80
http://www.zimtstangl.de/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de
81.169.244.118 301 https://www.zimtstangl.de/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 0.010 A
Visible Content: Moved Permanently The document has moved here . Apache/2.4.29 (Ubuntu) Server at www.zimtstangl.de Port 80
http://zimtstangl.de/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de
2a01:238:4368:c600:8352:fcee:fb4a:2655 -14 10.026 T
Timeout - The operation has timed out
Visible Content:
http://www.zimtstangl.de/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de
2a01:238:4368:c600:8352:fcee:fb4a:2655 -14 10.016 T
Timeout - The operation has timed out
Visible Content:
https://zimtstangl.de/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 404 42.117 A
Not Found
Visible Content: Not Found The requested URL /.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de was not found on this server. Apache/2.4.29 (Ubuntu) Server at zimtstangl.de Port 443
https://www.zimtstangl.de/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de -14 10.030 T
Timeout - The operation has timed out

Instead, there is a timeout.

So

  • remove your ipv6 AAAA entry, create a certificate, then fix your ipv6 (or)
  • fix your webserver configuration, so ipv6 works

Letsencrypt prefers ipv6, so this is critical. The redirect is ok.

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Oh thanks, I thought my local client prefers also IPv6 :frowning:

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