 Abstract: Due to various Denial-of-Service (DoS) attacks like blackhole and grayhole attacks, Mobile Ad-Hoc Networks (MANET) performance is degraded rapidly. These attacks have been detected and prevented separately by different techniques. In earlier research, hybrid black/grayhole attack detection was proposed in which blackhole and grayhole attacks were detected and prevented simultaneously based on the detection threshold. However, some malicious nodes are still present in the network by faking the threshold value and forwarding the fake message to the other nodes. Therefore, the hybrid black/grayhole attack detection is enhanced by integrating network metric measurements. In this paper, the Data-to-Control packet Ratio (DCR) is measured for removing malicious nodes from the network and also avoiding the false detection. In addition, fuzzybased mobility and traffic measurement is integrated with a hybrid DCR detection technique for removing malicious node links. Moreover, the optimal path for packet transmission is selected by measuring the queue delay based on fuzzy logic optimization. Finally, the efficiency of the proposed hybrid blackhole/grayhole attack detection technique is illustrated through the simulation results based on the throughput, packet drop rate, packet delivery ratio and routing overhead.