The document proposes a new method called Speedy IP Traceback (SIPT) to identify denial-of-service attacks. SIPT works by having routers insert the media access control (MAC) address of the client and the router's IP address into packets. This allows the destination to identify the attacker's boundary router and MAC address, tracing the attack path. Traditionally, mechanisms like ingress filtering, link testing, and packet marking have been used but have not kept pace with evolving attacks. SIPT provides a more direct way to find the router connected to the attacker.