Everything was working normally till I replaced a router. Windows 2012 R2 server (AD, DNS, DHCP) local domain. I installed the new router and forgot to turn off DHCP in the router. A windows 10 workstation started having problems connecting to a server based application. I found the mistake by using ipconfig, and turned off DHCP in the router. Workstation still won't connect. All mapped drives are disconnected. The network profile changed to "Private" and was disabled. I used powershell to change it to "public" but it is still disabled. I tried dis-joining the workstation from the domain and tried to rejoin. Error message is "An Active Directory Domain Controller (AD DC) for the domain could not be contacted". I can ping from the workstation to the DC and from the DC to the workstation by IP and name. Workstation A record is in DNS. I have tried turning off the windows firewall, ipconfig /flushdns, tried a static IP on the workstation, restart netlogon, restart server and workstation, verified discovery and file sharing are enabled. no luck yet. any ideas would be welcome.