How to go from BB SA to MBB full time?

Hi everyone! Currently a junior at a semi-target with a 3.85+ gpa and an upcoming 2022 summer IB analyst role at top BB (GS/MS/JPM). Even though I haven't done the internship yet, I really don't see myself doing IB full time (not interested in the traditional IB exits of PE/HF/VC) and would prefer to do consulting instead. How should I position myself to transition into an MBB role? How difficult is it? Do I start networking with MBB alumni from my school now or hold off until later? When do I start prepping for cases? Appreciate the help and advice!