Mobile ad hoc networks (MANETs) have become a remarkable technology for wireless communication in recent years because of its critical and emergency situations that may cover. Security is an essential issue in MANET due to open medium and absence of clear line of defense. This thesis is dedicated for providing a secure routing protocol for MANET with a large number of security services in the network layer. The proposed work integrates Internet Protocol Security (IPsec) protocol with three routing protocol for MANET; Ad hoc On demand distance vector (AODV), Optimized Link State Routing (OLSR), and Geographical Routing Protocol (GRP) to provide confidentiality, authentication, integrity, and access control for both routing information and data messages. The secure and unsecure networks are simulated under the effect of two types of attack: Intelligence Pulse Jamming Attack (IPJA) which makes Denial of Services (DoS) and Misbehavior Attack (MA) which performs malicious action of some nodes with respect to others. Several performance metrics taken into consideration to measure the overall performance of the network such are Throughput, Delay, Number of hops, Retransmissions attempts, Data dropped, Routing traffic sent and received. Simulation results using Optimized Network Engineering Tool (OPNET) Modulator demonstrated that throughput is degraded and the end to end delay rises in secure network. The Best throughput among these three routing protocols with IPsec integration is IPsec-GRP and the worst is IPsec-AODV, while the best end to end delay of the network is in case of IPsec-OLSR and the worst is IPsec-AODV. Network with security services under the effect of MA gives better throughput and worse delay than the network under IPJA influence.