When I try to connect the warehouse to a local database I get the following the error. DWC06200E An unexpected communications error has occurred.
Connection refused: no further information
RC = 6200 RC2 = 0

Just follow following steps:
--DB2 instance must be started
--Warehouse services must be started (server and logger, sometimes server only is started even if automatic start specified for both)
--your user-id must be agreed for DW databases
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if this is not enough just check with your firewall, I noticed two modules are to autorized for web access.
iwh2serv.exe and iwh2log.exe

jparis