On a Server 2016 Essentials computer, with a static address pool defined as explained in this post, the Routing and Remote Access service adds a second IP address to the server’s DNS.
In DNS Manager, the Forward Lookup Zones show two IP addresses for the server:
This means that computers on the network sometimes resolve the server’s name as the second IP address. I’m not sure that’s a problem, but I am having difficulty getting WSUS to register a new desktop to the server and I wonder if it’s because of this IP address ambiguity. (Update: I realized later that the WSUS problem was likely due to a cloned PC with a duplicate SID. See this post.)
There are numerous threads dealing with this issue. Apparently it has been around since at least Windows 2000 and has to do with the running RRAS on a DNS server (which is how Windows Server Essentials is intentionally configured).
Some threads refer to KB292822. A Google search for that article comes up with this document: Name resolution and connectivity issues on a Routing and Remote Access Server that also runs DNS or WINS. However there is no mention there of what seems to be the simplest solution, suggested in this post: to tell the DNS server to stop listening on the second IP address, in DNS Manager, just open the server’s Properties, go to the Interfaces tab, choose Only the following IP addresses, and de-select the second IP address.
After doing that, right-click on the server name and choose Refresh. The second IP should no longer appear in the Forward Lookup Zones.