We are using the MS Assessment and Planning Toolkit in order to determine the how ready we are for Office 365. When I run the assessment tool it traverses our networking using Activity Directory as a guide. About a dozen machines come back (some XP, Win 7, Win 8) with a full inventory of the machine. The problem is that the inventory is not collected on the other 100+ machines. Messages like "Failed - RPC Server Unavailable" or "Failed - Connection time out" are returned under WMI Status for all of the machines where the inventory failed. I cannot find a reason why it would work on a dozen machines and not work on the others. All of the machines are in AD and are in the same OU. Symantec Endpoint Protection is running on all of the machines using the same settings on all the machines.
Any suggestions are greatly appreciated.