AODV as specified in is a reactive routing protocol for MANETs. Only a node that requires a route toward a given destination broadcasts a Route REQuest (RREQ) packet. On receiving a RREQ, a node that maintains a valid route can directly answer. Otherwise, the RREQ is rebroadcasted again. The same operation is repeated until a path is found. A node that has an answer sends a Route REPly (RREP) packet toward the source node. The RREP tracks the reverse route already taken by the corresponding RREQ.