Mobile Ad Hoc Networks Are Infrastructure-Free, Pervasive, Andubiquitous and Without any Centralized Authority. These Unique Characteristics,Combined With Security Threats, Demand Solutions In Securing Ad Hoc Networksprior to Their Deployment In Commercial and Military Applications. So Far, Theresearch In Mobile Ad Hoc Network Has Been Primarily Focused on Routing Andmobility Aspects Rather Than Securing the Ad Hoc Network Itself. Due to Theever-Increasing Security Threats, There Is a Need to Develop Algorithms Andprotocols For a Secured Ad Hoc Network Infrastructure. This Paper Surveys Theprevailing Mobile Ad Hoc Network Security Threats and the Existing Solutionschemes. Current Technologies Andsecurity Advances Have Made Networked Systems and Applications Very Popular Andwidely Used. the Pen Asive and Practical Aspects of Wireless Mobile Ad Hocnetworks (Manet) Made Them Very Popular As Well. This Created the Need Forsecuring Manets to Provide Users With Authentic Communications, Secure Androbust Information Exchange, and Efficient Security Mechanisms. However, Manyof the Security Solutions Devised For Regular Networks Are Not As Efficient Noras Effective on Manets. This Paper Investigates the Security Issues of a Commontype of Manets (Open/Dynamic Vianet) at the Network Layer -Where Routingprotocols and Forwarding Mechanisms Are Used. In This Paper, We Identify Thedifferent Security Requirements Specific to Manets and Sun Ey some of Theavailable Secure Routing Techniques. T ...