Abstract: A Mobile Adhoc Network (MANET) is a continuously self-configuring, infrastructure-less network of mobile devices connected without wires. Each device in a MANET is free to move independently in any direction, and will therefore change its links to other devices frequently. Though each node in MANET will act as host as well as router, the security is a major issue and the chances of having the vulnerabilities and attacks are also more. Different types of attacker attempts different approaches to decrease the network performance, throughput. In this paper,I propose an enhancement of Request-bandwidth-time based on selective verification for limiting the impact of a replay attack.

Keywords: MANET,Replay attack,bandwidth,DoS attack.