Biblio
A Mobile Ad-hoc Network (MANET) is infrastructure-less network where nodes can move arbitrary in any place without the help of any fixed infrastructure. Due to the vague limit, no centralized administrator, dynamic topology and wireless connections it is powerless against various types of assaults. MANET has more threat contrast to any other conventional networks. AODV (Ad-hoc On-demand Distance Vector) is most utilized well-known routing protocol in MANET. AODV protocol is scared by "Black Hole" attack. A black hole attack is a serious assault that can be effortlessly employed towards AODV protocol. A black hole node that incorrectly replies for each path requests while not having active path to targeted destination and drops all the packets that received from other node. If these malicious nodes cooperate with every other as a set then the harm will be very extreme. In this paper, present review on various existing techniques for detection and mitigation of black hole attacks.