A method for mitigating denial of service attacks may include filtering out invalid packets from the received packets using a first filtering module, allowing the valid packets to pass through the first filtering module, and allowing some invalid packets to pass through the first filtering module. The method may also include passing the valid packets and the remaining invalid packets from the first filtering module to a second filtering module, filtering out more of the invalid packets using the second packet filtering module, allowing the valid packets to pass through the second filtering module, and allowing some invalid packets to pass through the second filtering module. The method may additionally include passing the valid packets and the remaining invalid packets to a protocol stack to filter the remaining invalid packets and pass the valid packets through to an application.