How do you get to undernet in Megaman battle network 3 blue

First, you must have the Tally from one of the Tora jobs. Go to Beach 2 and talk to the purple navi guarding the warp point. This will lead to HadesNet, where you will need to equip Press in the NaviCust to proceed. Having accomplished all of that, you will enter the Undernet, home of the baddest navis, the baddest viruses, the baddest tacos, the baddest everything, man.