Basic protection schemes against Denial-of-Service (DoS) are based on a perimeter-based model, where attacks are dealt with after they occur. This is quite often too late to prevent damage or loss of resources and service. The focus of this paper is to investigate a distributed defense method that can neutralize the attack before it reaches the potential target in mass. In order to effectively implement this method, this paper proposes a progressive, globally deployable sentinel scheme for data sampling, packet inspection, and DoS attack detection and recovery. A simulation framework is developed to study the performance of the proposed scheme. The results show a significant improvement in how the network deals with DoS attacks, in comparison to local DoS detection and prevention schemes.