Routing is the process to establish the communication path between
communicating entities to enable communication in any networking model by
forwarding the information in terms of packets. MANET is wireless
infrastructure free peer to peer network. Routing in MANET is establish based
on consideration that the nodes are cooperative. Malicious nodes do not
cooperate for communication activities such as they drop the packets. In order
to prevent malicious routing activities various intrusion detection and
prevention systems designed for MANET. The main objective of these systems
is to identify the malicious activities of the nodes by their packet operations. If
node drops the packet more than the predefined value than it considered as
malicious. But in MANET, reputed nodes also drops the packets if itbecomes
bottleneck intermediate node. Thus the work aims to examine the IDS
performance in the presence of bottleneck intermediate node. Further, the work
shows the importance of considering bottleneck intermediate nodeduring the
design of novel IDS.