Abstract
Mobile Ad Hoc Networks (MANETs) are an interconnected system of wireless nodes without any central administration, making them more vulnerable to attacks than their wired counterparts. One such attack is the "gray hole" attack, which affects the integrity of the MANET. In this paper we analyse the effectiveness of three MANET protocols: CGSR, TORA, and ZHLS under a gray-hole attack. Using the NS2.35 simulator, we study the impact of gray-hole attacks on the aforementioned protocols in terms of performance metrics such as packet delivery ratio, jitter and throughput. The results showed that ZHLS is more robust under a gray hole attack than its counterparts CGSR and TORA.