If it works without DNS since version 4.1 as you say, then why this post? I don't understand you...
You shut down the DNS server and vCenter didn't work anymore. DNS is a prerequisite for deployment and installation. This is clearly stated in the documentation. So why should it be different later in operation? The fact that you have only configured your environment with IP addresses is another matter. This is possible and supported.
Basically it is quite simple:
Does everything work without DNS if you only have IP addresses configured and no FQDNs? If so, then vCenter does not need DNS.
However, if you have "strange" behavior or errors without DNS, assume that vCenter still needs DNS for some reason. So simple.
An Internet connection is not needed, but then some features like the Online Health Checks and the Update Manager are limited.
---
Regards,
Sebastian
VCP6.5-DCV // VCP7-CMA // vSAN 2017 Specialist
Please mark this answer as 'helpful' or 'correct' if you think your question has been answered correctly.
