Mobile ad-hoc networks are vulnerable to several types of malicious routing attacks, black hole is one of those, where a malicious node advertise to have the shortest path to all other nodes in the network by the means of sending fake routing reply. As a result the destinations are deprived of desired information. In this paper, we propose a method AODV Robust (AODVR) a revision to the AODV routing protocol, in which black hole is perceived as soon as they emerged and other nodes are alerted to prevent the network of such malicious threats thereby isolating the black hole. In AODVR method, the routers formulate the range of acceptable sequence numbers and define a threshold. If a node exceeds the threshold several times then it is black listed thereby increasing the network robustness.