Early in my Let’s Encrypt journey I added a domain with a private IP address to a cert that had several other domains.
So one certificate covers these domains:
host1.example.com (public IP address)
host2.example.com (public IP address)
host3.example.com (public IP address)
host4.example.com (private IP address: 172.31.X.Y)
This has been working to provide https access for an internal component.
But I have become aware that this is non-standard, and possibly, impossible.
Is it supposed to work? How alarmed should I be about this usage?
(I checked some other topics and didn’t find this specific scenario)