I neeed to add a second domain controller to our network at another location to serve as a PDC and app/data server if the main PDC goes down. They need to have identical app software & data files. We have a T1 line between them now & are just sharing files presently. Thanks, JC

There are a number of considerations. Have you looked into the software licensing costs and how the products can both be running but having a shared database? There are 3rd party products that can mirror servers with the copy in a standby state. Something goes wrong the copy takes over. What I think you are asking is for how could you mirror servers between the sites via the T1 and perhaps how you would do this with W2KS only. Both servers would have to have all the apps installed. Sharing data remains a question due to the applications used. You would have AD working correctly. Each server would have to have the global catalog. You would have to setup some policies concerning what server which client machine authenicates to so you don't have T1 saturation. Good news is you can use dfs [distributed file system]to do the failover. See here: http://support.microsoft.com/default.aspx?scid=kb;EN-US;241452 Don't forget to consider the bandwidth cost of the server to server communication plus apps talking on the T1. Your T1 might not be a fat pipe [point to point] but frame relay which throttles you back to half of the stated port speed. Its called CIR [committed information rate]. So if you have 1.54mbps port speed you only get a 768k. I hope this was helpful. Best of luck!