I have problems renewing my certificate. I remember having lots of problem creating it the first time as well.
My webserver which uses the certificate (Home Assistant) is not on a standard port but I have made Apache available just for the sake of renewing the cert. Also tried standalone mode without Apache. For some unknown reason, certbot fails with connection timeout.
If I try to connect from an external server that I have access to, it connects fine to both port 80 and 443. Also if I try it with some random web service I found (http://www.t1shopper.com/tools/port-scan/).
Note! The firewall rules to allow 80 and 443 were only enabled when I did the certbot-auto-attempts, I deleted these two rules again afterwards.
My run with Apache option:
My run with standalone option:
my.domain.org is responding on port 443 (https).
Scan with curl from external server:
$ curl -I my.domain.org:80
HTTP/1.1 200 OK
Date: Fri, 09 Feb 2018 07:53:29 GMT
Server: Apache/2.4.18 (Ubuntu)
Link: http://my.domain.local/index.php?rest_route=/; rel="https://api.w.org/"
Link: http://my.domain.local/; rel=shortlink
Content-Type: text/html; charset=UTF-8
$ curl -I https://my.domain.org:443
curl: (60) server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none
More details here: http://curl.haxx.se/docs/sslcerts.html
curl performs SSL certificate verification by default, using a "bundle"
of Certificate Authority (CA) public keys (CA certs). If the default
bundle file isn’t adequate, you can specify an alternate file
using the --cacert option.
If this HTTPS server uses a certificate signed by a CA represented in
the bundle, the certificate verification probably failed due to a
problem with the certificate (it might be expired, or the name might
not match the domain name in the URL).
If you’d like to turn off curl’s verification of the certificate, use
the -k (or --insecure) option.
Why does LE have a problem connecting to my web server when “the Internet” does not?