Hey, I’m trying to expose my HTTPs server via Cloudflare. So, I did everything - I bought a domain and redirected it to my application, and also used “lets encrypt” certificate in order to serve my application in HTTPs. Now, whenever I use port 443 I get 521 from Cloudflare but if I switch to ano…

[image] edendror072: Also, I’m using the flexible mode That’s your problem. Switch to Full (strict) (or temporarily Full if your origin certificate has issues). On Flexible the connection from Cloudflare to your origin is over HTTP. Full and Full (strict) use HTTPS between Cloudflare and the…

Proxy traffic through cloudflare CDN to my HTTPs server fails with 521

Website, Application, Performance Security

erisa-cf November 16, 2023, 9:25am 5

There are also some tips here:

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Proxy traffic through cloudflare CDN to my HTTPs server fails with 521

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