Troubleshoot DC from client computer
Find logonserver from client
echo %logonserver%
Find who is DC
nltest /dsgetdc:xxx.domain.com.sg
To list DC with site
nltest /dclist:xxx.domain.com.sg
DCdiag to troubleshoot DC
dcdiag /V /D /C /E > c:\dcdiag.txt DCDIAG /TEST:CheckSecurityErrors