Now I want to introduce the use of ‘Configure Physical Nets‘, as follows:

　　If you has finished the PCB layout, as follows:

　　Then you want to get rid of these white wires, so the two boards would be separated completely. And you change the nets of the one board, as follows:

　　The earlier routes collide with the current routes, then you can use ‘Configure Physical Nets‘ to eliminate this problem, as follows:

Altium Designer 15 --- Nets Update