Adding a second physical site - 1 or 2 domains?

Question

I'm using Windows Server Essentials 2019 to manage the domain for a small business. It's running our DNS, DHCP and AD DS and has a fairly restrictive group policy in place, with an MS SQL server running on a second machine.

I'm adding a second physical site to my business in a different town. The staff from one premises occasionally work at the other site (but this is rare). I'm still going to be managing the network for the whole business.

My question is whether to add a second domain controller at the new site or whether to simply add the new site machines to the existing domain? Both sites have very good fibre connections and I would still be within the licensing terms of Essentials. I guess another solution would be to look at Azure domain services but I'm unfamiliar with this solution (I've been familiar with Windows Server since about 1999).

I'm not necessarily looking for "so this" or "do that" - but what should I take in to consideration?

Answer 1

From the point of view of productivity, one domain with 2 sites is quite enough. Moreover, you have a good Internet channel.

But from the point of view of reliability, it is better to have your own DC in every office. If there is no connection between the offices, this will help all employees to work without interruptions.

Answer 2

Your question appears a bit vague on the distionction between "domain" and "domain controller"; you don't need another domain, you need to add another domain controller to your existing domain (and configure Active Directory sites and replication accordingly).

This can be done even if you're using Windows Server Essentials: its requirements are that you can only have one of it and that it must be a domain controller, but you can have other DCs in the domain it manages.

Of course, an additional Windows Server license will be required for the new DC; but you will also gain much in terms of availability by having two DCs, one of them in each site.