2 things:
INE Workbook and videos are excelent preparation. Lab 4 being ugliest thing possible ;)
It takes a lot of mental power or what is proper word for it in English. There are A LOT of routers, and by the end of the day it's difficult to keep track of what's going on.
So goal of preparation should be to put strategic things like I-AS, CSC, mVPN in "hardware", and doing them without "thinking".
Regards
George
RS, SP #24777