An Intrusion Detection System is a network security technology originally built for detecting vulnerability exploits against a target application or system. The intrusion prevention systems extended IDS solutions by adding the ability to block threats in addition to detecting them and have become the dominant deployment option for IDS or IPS technologies. This article will elaborate on the configuration and functions that define the intrusion system deployment. An intrusion detection system only needs to detect threats and as such is placed out-of-band on the network infrastructure, meaning that it is not in the true real-time communication path between the sender and receiver of data. Rather, Intrusion solutions will often take advantage of a TAP or SPAN port to analyze a copy of the inline traffic flow.Thus ensuring that IDS does not impact inline network execution. IDS was developed this way because at the time the depth of analysis required for intrusion detection could not be performed at a speed that could keep pace with components on the direct communications path of the network configuration.As explained, the IDS is also a listen-only tool. The IDS monitors traffic and reports its results to an administrator or controller. But it cannot automatically take action to prevent a detected exploit from taking over the structure. Attackers are capable of exploiting vulnerabilities very quickly once they enter the network, rendering the IDS an inadequate deployment for prevention tool.