So I've got my computer in my bedroom, connected to the router downstairs via a switch, homeplug and another switch. I have Ubuntu and Win7 installed.
So I'm doing some Lua scripting in Ubuntu and suddenly the computer powers off instantly. No warning at all, other devices are unaffected, so not a powercut. I power it back on, boot into linux and there is no internet. Ping reports 'network unreachable'. I can find no working solutions online, so I boot into Windows. No internet either, no IP assigned, no DNS, 'general failure' for ping. Probably not an OS problem, since I hadn't used Windows for hours.
I assume that the router or network infrastructure must be the case. I reboot the router, get as direct a connection as I can, but with no luck. I put everything back, and just to be sure, I check a device branching off at the same point that my PC does: It can access the network and internet just fine. Not a network infrastructure problem.
I have no idea what's going on, and I consider myself to be an experienced computer techie. My motherboard is an ASUS P5N-D, latest bios, if that helps.