Routing Protocol for Low Power and Lossy Networks (RPL) has been standardized by the Internet Engineering Task Forceto efﬁciently manage the functions of the network layer when providing Internet connectivity for wireless sensor networks.RPL has been designed for constrained devices and networks. Owing to their constrained nature, RPL-based networks canbe exposed to a wide variety of security attacks. One of the most serious attacks in RPL is a black hole attack, where amalicious node silently drops all the packets that it is supposed to forward. This paper proposes a mitigation techniqueagainst black hole attack with low packet loss and high reliability. The proposed technique consists of a local decisionand a global veriﬁcation process. First, each node observes the communication behavior of its neighboring nodes byoverhearing packets transmitted by its neighbors and attempts to identify suspicious nodes based on their behavior. Inthe second process, if a node identiﬁes a suspicious node, then it veriﬁes whether the suspicious node is a black hole.We demonstrate that the proposed approach increases packet delivery rate signiﬁcantly and detects black hole attack effec-tively. Copyright © 2016 John Wiley & Sons, Ltd.