Intrusion Prevention Systems (IPS) are network security appliances that monitor network and/or system activities for malicious activity. The main functions of an IPS are to identify malicious activity, log information about said activity, attempt to block/stop activity, and report activity. The primary difference between an IPS and an IDS (intrusion detection system) is that an IPS is placed inline and has the ability to block malicious traffic.
The HP TippingPoint Intrusion Prevention System (IPS) delivers the most powerful network protection in the world. The TippingPoint IPS is an in-line device that is inserted seamlessly and transparently into the network.
Tipping Point IPS Overview.