Hi,
or use pcb-gcode, a freely downloadable utility that attaches to Eagle and generates Gcode direct from your .brd file,
no sending files anywhere.....the gcode is generated within 10 seconds or so and is (or can be) Mach3/Mach4 ready.
It generates, at your option, Top Etch, Top Drill, Top Mill, Bottom Etch, Bottom Drill, and Bottom Mill. You can set etch, drill
and mill depths at will.
Craig