The web/cloud world is so much nonsense. First, why do you even need HTTPS on a trusted network. Also if you want a trusted network, why not just use IPSec? HTTPS was specifically built to work over the Internet because it was too hard to switch from IPv4.
Second, if it's private, surely you can just use your own Certificate Authority, instead of paying a tax to be listed on someone else's Certificate Authority.
Second, if it's private, surely you can just use your own Certificate Authority, instead of paying a tax to be listed on someone else's Certificate Authority.