The primary concern for the deployment of MANET is to promote flexibility, mobility and portability. This mobility causes dynamic change in topology and poses challenges for designing routing algorithms. In the past few years, many ad hoc network protocols have been developed and research is still going on. It becomes quite difficult to say which protocols may perform well under different network scenarios such as varying network size, mobility of nodes and network load etc. This paper analyzes the performance of proactive protocols like DSDV, OSLR, reactive protocols like AODV, DSR and hybrid protocol such as ZRP. The analysis guides us to the evaluation of various performance metrics such as throughput, packet delivery fraction, normalized routing load and average end to end delay under different scenarios such as varying network size, speed of the node and pause time. The focus of this paper is to have quantitative analysis to guide which protocol to choose for specified network and goal.

Mobile Adhoc NETwork (MANET) consists of mobile nodes that can move freely and route packets without aid of centralized infrastructure. Dynamic changing topology, limited battery power and lack of centralized trusted authority make it vulnerable to several attacks and lot of research is being carried out in the field of security by discovering attacks, evaluating the damage caused to the network and developing solutions to combat such attacks. This paper simulates one of the most malicious behaviors known as blackhole attack. The blackhole node creates forged reply, advertising valid and fresh route to destination and thereafter drops data packets maliciously. The analysis guides us to the various performance parameters such as throughput, packet delivery fraction, normalized routing load and number of dropped packets evaluated over different scenarios.

In this paper, we discuss the basic routing technique of ants and study the change in pheromone values at each node. Also the optimal paths can then be computed based on the shortest cumulative pheromone count between source and destination nodes. AntNet is a distributed multi-agent system inspired by the stigmergy model of communication observed in ant colonies. The ants or control packets collect information about the network conditions and are used to update and maintain the routing tables. Ants based routing is gaining more popularity because of its adaptive and dynamic nature. A number of Swarm Intelligence based, more specially Ant Colony Optimization (ACO) based routing algorithms are proposed by researchers. A version of ant routing protocol called AntNet has been implemented to work within the network simulator ns-2. Routing tables and Pheromone tables have been computed for each node in the network. On the basis of these tables we have tried to compute the shortest and most optimal path between source node and destination node.