[Bimmer540]

When you connect ICOM to a car, the ZGW(FEM-GW/BDC) is given a IP-adress based on your ICOM DHCP setting.

What you need to do if you want to quickly swap to a ENET cable is either let the ZGW go to sleep (disconnect ICOM and let it fall asleep 10-20 min) or you could go into ISTA -> Service Functions -> Body, Voltage Supply -> Send power down command

Then you only have to wait 2-3 minutes for the car to fall asleep.