Cert not due for renewal, but simulating renewal for dry run
Plugins selected: Authenticator nginx, Installer nginx
Renewing an existing certificate
Performing the following challenges:
http-01 challenge for itbc-sgw.ddnss.de
Waiting for verification…
Cleaning up challenges
Attempting to renew cert (itbc-sgw.ddnss.de) from /etc/letsencrypt/renewal/itbc-sgw.ddnss.de.conf produced an unexpected error: Failed authorization procedure. itbc-sgw.ddnss.de (http-01): urn:ietf:params:acme:error:connection :: The server could not connect to the client to verify the domain :: Fetching http://itbc-sgw.ddnss.de/.well-known/acme-challenge/nq-sNp6mIbetssg_8OBxHIdlSHcJnZXVHik128v6oJA: Timeout during connect (likely firewall problem). Skipping.
All renewal attempts failed. The following certs could not be renewed:
/etc/letsencrypt/live/itbc-sgw.ddnss.de/fullchain.pem (failure)
** DRY RUN: simulating ‘certbot renew’ close to cert expiry
** (The test certificates below have not been saved.)
All renewal attempts failed. The following certs could not be renewed:
/etc/letsencrypt/live/itbc-sgw.ddnss.de/fullchain.pem (failure)
** DRY RUN: simulating ‘certbot renew’ close to cert expiry
** (The test certificates above have not been saved.)
To fix these errors, please make sure that your domain name was
entered correctly and the DNS A/AAAA record(s) for that domain
contain(s) the right IP address. Additionally, please check that
your computer has a publicly routable IP address and that no
firewalls are preventing the server from communicating with the
client. If you’re using the webroot plugin, you should also verify
that you are serving files from the webroot path you provided.
There may not be an IPv6 address on your system, but there is definitely an IPv6 address in your public DNS zone:
As noted previously (and confirmed):
:: may not be localhost but some systems do resolve (interpret) it that way:
ping :: PING ::(::) 56 data bytes 64 bytes from ::1: icmp_seq=1 ttl=64 time=0.036 ms
Try for yourself: nslookup itbc-sgw.ddnss.de 8.8.8.8 nslookup itbc-sgw.ddnss.de 1.1.1.1
[edit - technically :: equals 0:0:0:0:0:0:0:0 so requests to that address would be heard by the local system and replies to (much like an all F broadcast): ping 0:0:0:0:0:0:0:0 PING 0:0:0:0:0:0:0:0(::) 56 data bytes 64 bytes from ::1: icmp_seq=1 ttl=64 time=0.017 ms]