The power up in a big switch depends on how big it is and what CPs it has and the software version. With old Motorola processors and old software release I first powered up all the netwotk cores first but with no net, misp, pri/dti card enabled. Once the system had loaded completely and the midn routines passed I started to slowly enable all the pri cards, and the net cards. finally I powered up all the IPEs. This is a slower procedure but it's proven to be a safer way, plus you have more control.