• M. Santhi Sri
• K.Srinivasa Rao

A mobile ad-hoc network (MANET) infrastructure less dynamic network consists of collection of wireless mobile node that communicates with each other without the use of centralized network. Security in MANET is the most important concern for the basic functionality of network. The malicious node falsely advertises the shortest path to the destination node during the route discovery process by forging the sequence number and hop count of routing message .This paper primarily focused on how black hole and gray hole attack reduces the network performance. Gray hole attack is an event that degrades the overall network’s performance by intentional malicious activity. Gray hole attack may drop packet coming from or destined to certain specific nodes in the network while forwarding all the packets for other nodes. The black hole attack might take place because of the malicious nodes that are consciously misbehaving and has smashed node interface. In this paper, an overview of MANET has been presented with its issues, routing protocols with its characteristics. This paper also concentrated on different defense mechanisms that are available to detect and mitigate black hole and gray hole attacks. In this paper, we have discussed various techniques of detection and avoidance of Black hole and gray hole nodes in MANET using secure AODV routing protocol.

MANET, AODV, SAODV, Black Hole Attack, Gray Hole attack

"Prime Product Number and Armstrong Number based Malicious Node Detection Scheme in SAODV", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.5, Issue 11, page no.570-578, November-2018, Available :http://www.jetir.org/papers/JETIR1811074.pdf

"Prime Product Number and Armstrong Number based Malicious Node Detection Scheme in SAODV", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.5, Issue 11, page no. pp570-578, November-2018, Available at : http://www.jetir.org/papers/JETIR1811074.pdf