Using a Letsencrypt Certificate on a Subdomain

Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. crt.sh | example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.

My domain is: admin.quiltinaday.com

I ran this command:

It produced this output:

My web server is (include version): nginx

The operating system my web server runs on is (include version): Ubuntu 22.04

My hosting provider, if applicable, is: AWS EC2

I can login to a root shell on my machine (yes or no, or I don't know): Yes

I'm using a control panel to manage my site (no, or provide the name and version of the control panel): no

The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot): 2.8.0

I have created a new Linux server on AWS that is going to be a subdomain of a Windows server that has a GoDaddy certificate. I have created 2 A records: admin.quiltinaday.com and www.admin.quiltinaday.com that are pointing to the new server. The instructions I saw stated that I need a www record for Letsencrypt. Do I need the www.admin.quiltinaday.com DNS record? Can I create a certificate with letsencrypt for the new server that will not conflict with the Windows server?

Need, no.

It's only useful if you want to use the www 4th level (sub)domain.

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The server the DNS IP points to is queried to satisfy the HTTP Challenge. So, if admin subdomain points to your Linux that's where you run Certbot and make the cert for that domain.

Your other server won't know anything about that.

One "server" is not a "subdomain" of another server. The DNS A (and AAAA) records are placeholders for the IP address. These can point to the same server or different ones.

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