I am going through a list of domains on my server,
and using lets encrypt - is it possible to give a cert for the actual plesk /I.P. address?
when i check the I.p. address I am getting a “mismatch” COMODO SSL Analyzer
v1.0.13
Certificate Details
Common Name wmysite.com MISMATCH
No, Let’s Encrypt doesn’t offer certificates for IP addresses, only for fully qualified domain names.
Not issuing certificates for IP addresses is something that applies to all Public CAs not just LetsEncrypt
That's not entirely correct: the baseline requirements only restrict certificates for private IP addresses (called Reserved IP Address there). For public IP addresses, it is perfectly possible to get a certificate for, just not from Let's Encrypt (I don't know why).