@Pete-S said in Production KVM server "hardening"?:
VPN is used to get access to the private network. Servers are not accessible from internet.
This is the part that is weird. Like.... if we look at it from the outside, it's the same...
Step One: Access exposed port
Step Two: Access server
That behind the scenes it's a private network is irrelevant to someone attempting to access it. In both cases it's a published port that is heavily locked down with encryption and MFA. If you want, you can call the SSL layer of SSH a VPN (it literally is, in every sense) and you can call the inside of that tunnel a private network (it is in any meaningful sense) and voila, the two thigns are the same other than the double encryption which isn't "bad" but isn't beneficial either (typically.)
A bit of pain, no gain. But putting on my security auditor's hat.... it's a bit of "making people annoyed at pointless security" which is, itself, a huge security hole that creates risk. When you make security too onerous, and especially if there is no security justification for it, you typically create both a business need and an emotional desire to circumvent the security.