I'm struggling to get the Eagle Autorouter (Eagle 7.6) to route only the VCC (layer 2) and GND (layer 15) layer on a 4 layer board. I have created a net class for VCC and GND. Now I would like to have a separate "routing pass" for GND and for VCC.
What I want it to do is just add vias on all GND and VCC pads to the respective layer and don't create traces where possible (only for through hole components f.e.). E.g. use the shortest path to the respective layer instead of drawing and connecting traces to the PSU.
I tried setting the cost of all layer but the GND or VCC layer to 99 and the cost of vias to 0 but I always end up with all signals routed, not just the GND signals.
How do I accomplish this?