The mobile ad hoc network is the type of network which is decentralized in nature. In the mobile ad hoc network nodes simply configure together to form the network. In the network single hop and multi-hop type of communication is possible which forms direct and indirect type of communication. When the two nodes are in the range of each other they can directly communicate with each other through direct communication. In the mean while multi-hop type of communication is the one in which nodes can indirectly communicate through intermediate nodes.
To establish secure and efficient path from source to destination various types of routing protocols proactive and hybrid. In the reactive routing protocols nodes gather the network information to establish path to destination. In the proactive routing protocols the source node uses the network predefined information to establish path to destination. In hybrid routing protocol source gather network information and also uses predefined information for the path establishment to destination. Due to self-configuring nature of MANET, many malicious nodes may join the network which are responsible various types of active and passive attacks. In the MANET routing, security and QoS are the three major issues which can be resolved in future to make communication more efficient and reliable. came into existence in the recent time. The routing protocols are broadly classified into reactive,