SSL/TLS Issue with Let's Encrypt and Cloudflare in Full Strict Mode

Hi everyone,

I’m facing an issue with SSL/TLS on my subdomain www.subdomain.domain.dev. I’m using Cloudflare in Full Strict mode. I have tried both Cloudflare’s managed certificate and a Let’s Encrypt certificate generated on my server, but I keep getting the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error. Here is a brief overview of my setup:

  • Cloudflare SSL/TLS settings: Full Strict
  • Tried both Cloudflare Universal SSL and Let’s Encrypt certificate
  • Ingress configuration in Kubernetes seems correct

Any help or insights would be greatly appreciated!

Thank you!

Welcome to the Cloudflare Community. :logodrop:

Among other issues, you most likely are encountering the subdomain too deep issue due to your use of www in front of your subdomain.

Regardless of your choice of Let’s Encrypt or a Cloudflare Origin CA certificate on your origin server, you should only ever choose Full (strict) for your encryption method.