Learn how to fix the Challenge failed for domain in Certbot Apache. Our Apache Support team is here to help you with your questions and concerns.

Challenge failed for domain Certbot Apache – About

Some of our customers have been running into the following error when Certbot cannot complete the required domain validation challenge for a particular domain during the certificate issuance or renewal process.

Interestingly, this error is often seen when our customers use the Certbot Apache plugin to automate the certificate setup for an Apache web server. Fortunately, our experts have a solution.

When obtaining an SSL/TLS certificate from Let’s Encrypt, the CA has to verify that we have control over the domain for which we are requesting the certificate.

This is where Let’s Encrypt relies on the domain validation process. Furthermore, it involves different challenge types as seen here:

• HTTP-01 challenge:

  Here, Certbot creates a certain file with a random token on our web server’s document root. Then, it asks the Let’s Encrypt server to retrieve that file over HTTP. If the file is accessible, the domain is considered validated.
• DNS-01 challenge:

  In this challenge, Certbot needs us to a certain DNS TXT record containing a random token in your domain’s DNS zone. Then, Let’s Encrypt’s server checks for this TXT record in order to validate the domain.

Causes & Fixes

Now, let’s take a look at some of the common reasons behind the error and how to fix them:

• Web server misconfiguration:

  If the web server is misconfigured, we are likely to run into the error. It prevents Certbot from serving the required challenge file for HTTP-01 validation.

  We can resolve this by ensuring that our Apache server is correctly configured. Furthermore, we have to verify that the DocumentRoot is set to the correct directory where Certbot can place the challenge file.
• Firewall or network issues:

  Another cause for the error includes firewall rules or network configurations that may block Let’s Encrypt’s servers from accessing the challenge files.

  We can fix this by modifying the firewall rules or network configurations to ensure access to the challenge files on port 80 (HTTP) or port 443 (HTTPS).
• DNS propagation delays:

  In the case of DNS-01 challenges, sometimes the DNS changes may not have taken place across all DNS servers. This causes the Let’s Encrypt server to fail to find the required TXT record.

  In this case, we have to verify that the required TXT record has been created and propagated across all DNS servers.
• Server downtime:

  The error also occurs when the web server is down or has issues during the certificate issuance or renewal process. Hence, always ensure the web server is running and accessible to avoid an error message.

Furthermore, if the Apache plugin continues to fail, we can try the consider the standalone plugin or the DNS plugin for Certbot instead.

Let us know in the comments which one of the above tips helped you resolve the error.

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Conclusion

In summary, our Support Techs demonstrated how to resolve the Challenge failed for domain in Certbot Apache.