I have reached the stage where you recommend running the scripts to set the IP address of the opposite DC to be the DNS server.
From the new server ,\SetDNSonWSE2019.ps1 sets the IP of the DNS server to the old server and the alternative to 127.0.0.1 - correct
From the old server I run .\SetDNSonWSE2012.ps1 and input the IP address of the new server It first returns the following message "There are no Domain Name Servers (DNS) configured on this computer." and then sets the preferred DNS server to itself with 127.0.0.1 as the alternative.
The line to install the roles ran ok and the AD shares for NETLOGON and SYSVOL are present on both servers. There is also a DNS server running on the new server.
Should I just manually set the DNS server to the new server from the old?
Not sure why it does that but can you set preferred DNS server IP address to the new server on the old server alternative to 127.0.0.1. Pls, post an ipconfig /all from both servers to see if all is OK?
I also note that there are two forwarders on the old server that are set to the DNS server address of the ISP. On the new server one forwarder has been set which points back to the old server. All other entries appear to be as expected with the Forward Lookup Zone for the AD Domain populated as expected.
That is as expected.
ipconfig outputs attached, thanks