We have inherited a client that has a Windows 2012 Server as a domain controller. We noticed that DNS and DHCP are running on the firewall, not the server. We know that is not a recommended solution, but they have been running for six months with no issues. Apparently, they were having connectivity issues before they made the change.
What is the potential drawback to keeping things the way they are? Will Active Directory not function properly? Also, is it a relatively simple process to move the roles back to the server?