I have a WordPress website hosted by HostGator and I want a subdomain to redirect to my Application server. The problem is that after adding the subdomain (type “A” in the dns list I get a 521 error. After reading troubleshoot, I think the probable cause is the SSL configs, since the server is bare NGINX + Node.js hello world without ssl configs and typing the server IP in the browser it answers. The Cloudflare troubleshoot docs tells to configure a CA origin and I would need to pay annually to DigiCert, but I want it free using let’s encrypt. I couldn’t configure let’s encrypt, it returns this error (I faked the address for this post)
Domain: www.aaa.bbb.ccc
Type: None
Detail: DNS problem: NXDOMAIN looking up A for www.aaa.bbb.ccc -
check that a DNS record exists for this domain; DNS problem:
NXDOMAIN looking up AAAA for www.aaa.bbb.ccc - check that a DNS
record exists for this domain