Setup ESXi with AD authentication

Setup ESXi System for AD authentication

Add group to AD called 'esx admins' and populate with your administrators for esx

Add domain controllers to DNS

Go to DNS and Routing in Configuration tab

Set the DNS servers to AD controller IP's

Set the 'look for hosts in following domains' to your current domain

Now you need to change the NTP settings per this document
https://kb.vmware.com/selfservice/search.do?cmd=displayKC&docType=kc&docTypeID=DT_KB_1_1&externalId=1035833

once that is done follow these steps
https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2075361

1. From the vSphere Client, select the host that you want to add to the Active Directory.
2. Click the Configuration tab 
3. Click the Authentication Services.
4. Click the Properties link at the top right pane.
5. In the Directory Services Configuration dialog, select the directory service from the dropdown.
6. Enter a domain.
7. Click Join Domain.
8. Enter the user name (in user@domain.com format) and password of a directory service user account that has permissions to join the host to the domain and click OK.
9. Click OK to close the Directory Services Configuration dialog box.

You should now be able to login to the ESXi box using your AD users that are in the 'esx admins' group.