What type of SSL does a FTP sub domain, WWW or NON-WWW require?

Question

We have a few web servers and an FTP server that sits behind our public IP that is used for a few applications. We need to get an SSL Certificate that I can install on each of the servers to pass PCI requirements.

Currently, I have been using self-signed certs but that’s not good enough for the standard so I have to buy a publicly trusted one. All of the servers are reached through the same FQDN that points at the IP address.

These are the domains and their sub domains:

• ftp.example.com
• non-www example.com
• with-www www.example.com

Will a basic cert work? I guess I’m confused as to whether the ftp.domain counts as a subdomain or not. All the other servers are separated buy for and forwarding at the firewall level.

Answer 1

Simple SSL certs cover the main domain (example.com) and one fixed sub-domain (www.example.com), if you want to use a custom sub-domain such as ftp.example.com then you will need to purchase a CERT that supports additional subdomains.