User blog comment:ZeroExalted/Is anyone here an expert on DDOS or other hacking issues...?/@comment-4713738-20120314100019/@comment-4713738-20120314100705

There is no more question whatsoever. You are being DOS attacked, and whoever's doing it is pretty damned knowledgeable and determined. Luckily, a smurf attack is an easy fix. If you haven't already done so, configure your router not to respond to ping requests.