> The replication is not working down to the W2K site or back > up to the NT4 hub server. What do I need to change to make it work > please? I spent days figuring this one out on my own. Read the following TID very carefully. Note that you need two ADC's for directory sychronization to work: 1) From Win2k AD to the Exch2k SRS. 2) From the Exch2k SRS to Exchange 5.5. http://support.microsoft.com/default.aspx?scid=kb;EN-US;q300129