Mobile Ad hoc NETwork (MANET) consist of independent mobile nodes without any fixed infrastructure. All mobile nodes cooperatively transfer their data packets to other mobile nodes in the network within their transmission range. Mobile nodes depend on intermediate nodes when transmission range beyond limit (i.e.), multi hop network. Various attacks are possible in MANET due to its open environment and dynamic nature. Security is important to avoid those attacks. This paper analysis various Intrusion Detection System (IDS) to avoid packet data loss in network.