Question
Certbot SSL error "Unrecognized challenges: tls-sni"
- Posted on October 6, 2023
- Security
Asked by e7a6d5efa06d4211b4526cc1a86c2c
When I am try8ing to create an SSL certificate on port 443, I get the following error:
certbot: error: argument --preferred-challenges: Unrecognized challenges: tls-sni
Port 80 is already in use, so I am following the instructions of using “–preferred-challenges tls-sni” but it does not seem to be working.
Not sure if I am missing anything. Following this tutorial: https://www.digitalocean.com/community/tutorials/how-to-use-certbot-standalone-mode-to-retrieve-let-s-encrypt-ssl-certificates-on-ubuntu-1804
This textbox defaults to using Markdown to format your answer.
You can type !ref in this text area to quickly search our full set of tutorials, documentation & marketplace offerings and insert the link!
These answers are provided by our Community. If you find them useful, show some love by clicking the heart. If you run into issues leave a comment, or add your own answer to help others.
Featured on Community
Get our biweekly newsletter
Sign up for Infrastructure as a Newsletter.
Hollie's Hub for Good
Working on improving health and education, reducing inequality, and spurring economic growth? We'd like to help.
Become a contributor
Get paid to write technical tutorials and select a tech-focused charity to receive a matching donation.
Heya,
The error you’re encountering is due to the deprecation of the
tls-snichallenge by Let’s Encrypt. This challenge method is no longer supported because of some identified vulnerabilities.As for PORT 80, what is listening on that port? You can check by running: