While trying to install the certificate, I get “Failed to connect to host for DVSNI challenge” error message. I tried this by using the standalone plugin command
sudo ./letsencrypt-auto certonly -a standalone -d xxx.yyyy.com --server https://acme-v01.api.letsencrypt.org/directory
My domain is hosted in AWS EC2. I have ensured that the ports 80 and 443 are open. I’ve also checked all the threads related to this subject with no luck. Need some help is resolving the issue.