MANET is a wireless ad-hoc network which includes mobile nodes. In MANET mobile refers to the movable nodes which can change their location frequently. MANET is a network which has no central infrastructure; it is a self-managing and self-configuring network. In MANET devices can be heterogeneous like laptops, mobiles, PDAs, etc. Due to the mobility of the nodes and no infrastructure mobile ad hoc network can be used in disaster and emergency situations. Mobile ad-hoc network has the features of dynamic topology, multi-hop routing, energy constraint and easy setup. The nodes in the MANET work as a both host and a router, to make routes in the network. Due to all these flexible features of MANET there are many security vulnerabilities arise. In MANET routing is a main concern due to the mobility and the node work as a router. The security of the routing layer is essential because if any attack interrupts the communication security of whole network can be compromised. There are different types of attacks in MANET: internal attacks, external attacks, active attacks and passive attacks. The attacks of network layer are identified in this paper. Some routing protocols are used for the security of MANET like SAODV, SRP, SEAD and Ariadne etc. In this paper, we present a review of routing attacks and their possible solutions for example, how to avoid f these attacks.