I know Microsoft do not support "graft and prune" as a migration strategy, but could it work as a short term solution if the 2 private networks are split and no longer communicate? If the splitting company takes its local Forest Root DCs, cuts communications with the parent company, and forces one of those root DCs to take on the FSMO roles, could it then remove all other child domains except its own and operate independently blissfully unaware that the other company is also running the same forest name and IDs on its own network (minus the child domain that is splitting)?
Windows 2008 R2 throughout, no Exchange servers to worry about, DNS is all run off UNIX. The child domains have always been run locally in each country, its just they have been part of the same forest. A migration to a new forest is not feasible in the near term, but will be the natural goal when resources can be decommissioned and other dependencies removed to vastly simply the task.
It doesn't matter that it is a "dirty" solution, but could it work?
Thanks in advance.
