MANET is a collection of wireless independent nodes along with transmitter and receiver that communicate with each other via bidirectional link. The self-configuring ability of nodes in MANET made it popular among critical mission applications like military use or emergency recovery. But due to the changing topology and open access MANET become vulnerable to problems (such as receiver collision, limited transmission power, false misbehaviour report , packet dropping) To solve this problem we use three approaches of Intrusion Detection System (IDS) such as Watchdog, TWOACK, and AACK. We have proposed a new protocol design for MANET that is IDS based EAACK which consist of ACK, S-ACK and MRA for solving all the problems of Watchdog approach in IDS of MANET.