Kind of continuing where solution to this topic has lead me to.
I am in process of replacing an existing SBS 2008 to a new Windows Server 2016 Essentials within the same Domain. And I do not have much beckground especially in Windows. The step I am at in the Migration process is to add the new Server to the existing Domain (worked) and then promote the Essentials Server to a Domain Controller. I choose the Option to "Add a domain dontroller to an existing domain" and am confronted with the 'Domain Controller Options' which look like this:
[+] Domain Name System (DNS) Server
[+] Global Catalog
[ ] Read only domain Controller (RODC)
I am wondering a Little if RODC shouldn't be checked, as I was not expecting to be the "boss in the ring" with the new Server Right away.