[PROBLEM]
I was playing around with WOL (wake on lan), and I've downloaded
'wol' from http://ahh.sourceforge.net/wol/ - but the target machines simply didn't show any response to the 'magic packets'
[SOLUTION 1]
It seems that the OS must enable the WOL functionality after shutdown (which is the case when telling Windows to 'shutdown'), but this is NOT the case when the PC was started and turned off BEFORE Windows. (whose sick idea was this?)
[SOLUTION 2]
I've tried the following
'wol -h 192.168.1.15 00:02:54:23:A0:B5'
...using the exact IP of my test-target, but it should have been the broadcast address of the desired subnet.
'wol -h 192.168.1.255 00:02:54:23:A0:B5' works perfectly now.