Is my Realtek NIC fried?

[lpgunit]

I'm worried and anxious about the internal NIC on my ASUS motherboard being potentially damaged recently. It all happened when, for some reason, my wireless extender box gave up on me not too long ago. At first I thought it was just the router itself, but I connected the DSL modem to my rig and while it initially worked and was able to acquire a DNS address, unplugging the cable and reconnecting it again resulted in this on the terminal upon keying in the ipconfig /all and nslookup commands:

Address: fec0:0:0:ffff::1

I was thus unable to browse the web from that point on; releasing and renewing the lease does the trick, and changes the address back to 192.168.1.1, and I am able to get back online by forcing a different DNS server as well. It just irks and worries me that reproducing the problem doesn't yield the same issue with another PC i.e. plug it in on the ethernet jack, wait for a few minutes, unplug it and then replug it again. I tried reinstalling the driver to no avail, and went so far as to downloading and running SystemRescueCD to check if it's just Windows being bonkers, but the symptoms seem to persist regardless. I am running out of options right now, and I'm not that arsed to tell my folks about having the board RMA'd either.