I have recently migrated from NT 4.0 to W2K with active directory. The first W2k server is the mail server and the first Active directory domain and is also setup as pre-windows 2000 mode. Now I've added an additional domain controller, but if the first one is down, it takes 15minutes to login. Any ideas? Is there more work to be done? Do I move the server to native mode and are there any implications?