I want the following config for BES infrastructure:

srp.na <-- BES-1 --> configDB-1
srp.ap <-- BES-2 --> configDB-1

I'm wondering if I move users from BES-1 to BES-2, does the user need to reactivate the blackberry?

Thank you.

As long as it stays on the same database, it is not necessary to activate again. We have just that setup and moving between BESs (even when the BESs point to different RIM relays) is not a problem and requires no action on the device (assuming all are at version 4.x).

Great! Thank you.

RIM recommends you move in groups if you were planning any mass moving .. I think it's 100 or less at a time. I'd recommend doing this in the off hours so your users won't be impacted as there is a slight delay until the service books update to the new SRP.