We have 4 Windows 2008 R2 domain controllers (DC), 2 at each site connected via firewalls. Can anyone tell us why they are trying to communicate over tcp/45003-45007 ports? The main service failing is lsass.exe. We cannot find any documentation from Microsoft stating that Active Directory should be using this port range. For compliance reasons we cannot open these ports without backup documentation. Can anyone help explain why all 4 of our DC’s are using these ports (45003-45007)?