While technical solutions for blocking spoofed traffic exist they are only effective and applicable close to the edge – computers and other end-devices connected to the net. Spoofed Internet traffic is a persistent threat, and often the root cause of reflection Distributed Denial of Service (DDoS) attacks. The edge of the Internet is an unruly place” Introduction
Nowhere in the basic architecture of the Internet is there a more hideous flaw than in the lack of enforcement of simple SAV (source-address validation) by most gateways.