In this paper a technique for intrusion detection in MANET has been proposed where agents are fired from a node which traverses each node randomly and detect the malicious node. Detection is based on triangular encryption technique (TE) where AODV is taken as routing protocol. For simulation we have taken NS2 (2.33) where two type of parameters are considered out of which number of nodes and percentage of node mobility are the attributes.For analysis purpose 20, 30, 30, 40, 50 and 60