"Error Code 2103 when Adding an External SSL Certificate to Cloudflare"

Hello Cloudflare Community,

I am facing a technical challenge while configuring a subdomain from an external provider on Cloudflare and I am seeking your assistance. I am not an expert in this area, so any help would be greatly appreciated. Here are the details:

  • I have a subdomain, sub1.monsite1.com, configured on Cloudflare with a universal SSL and connected to a load balancer lb1.monsite1.com.
  • I am trying to add another subdomain, sub2.monsite2.com, which is not initially on Cloudflare, with its own SSL certificate from a different provider.
  • When attempting to add the SSL certificate for sub2.monsite2.com to Cloudflare, I encountered the error “Error Code 2103 - The certificate chain you uploaded does not include any hostnames from your zone.”

My specific questions are as follows:

  1. How can I resolve the Error Code 2103 when adding the SSL certificate for sub2.monsite2.com on Cloudflare?
  2. Are there specific steps or configurations required to ensure that this external SSL certificate is recognized and functions correctly with Cloudflare?

I would also like to know how to properly configure the redirection of sub2.monsite2.com to sub1.monsite1.com in this context.

Thank you in advance for your support and expert advice to help me navigate through this setup.

Best regards,

Have you tried the steps here?

I have a client who manages the subdomain sub2.monsite2.com and has requested a CNAME record to point to this domain. Therefore, I provided them with sub1.monsite1.com. However, the issue arises in my monsite1.com zone, where I am unable to apply their SSL for sub2.monsite2.com. I believe I might be misunderstanding the correct approach to this problem.

The core issue seems to be related to the Subject Alternative Name (SAN), as the SAN for monsite1.com does not match monsite2.com. Consequently, this mismatch is preventing me from adding an edge certificate. I’m seeking guidance or a solution to this problem, as I understand there’s a conflict due to the differing SANs, but I’m not sure how to resolve it.

TY