Unfortunately the way NTP works - if it cannot communicte with an upstream, it's not considered reliable, and therefore, it's nothing that your clients (esxi hosts) will talk to.
JarryG wrote:
Well, it depends on services you are running. We had a lot of problems with out-of-sync time
Wait until your domain controllers stop talking to each other because kerberos won't authenticate, due to a timeshift of < 1 hour.