This paper discusses an enhanced AODV routing protocol as a method for defence against JellyFish (JF) Delay Variance attack in Mobile Ad-hoc networks. The JF delay variance attack introduces delay in forwarding the packets at network layer. It uses MAC addresses to calculate the route for forwarding the packets to destination. The attacker node creates delay in forwarding the packets, which increases end-to-end delay and decreases throughput of the network. Thus the performance of network decreases drastically. We propose an enhancement in AODV protocol so as to detect the malicious nodes in a network and to remove them from the routing path without their knowledge.