Intrusion prevention system

Intrusion prevention systems (IPS), also known as intrusion detection and prevention systems (IDPS), are network security appliances that monitor network and/or system activities for malicious activity. The main functions of intrusion prevention systems are to identify malicious activity, log information about this activity, attempt to block/stop it, and report it.

Intrusion prevention systems are considered extensions of intrusion detection systems because they both monitor network traffic and/or system activities for malicious activity. The main differences are, unlike intrusion detection systems, intrusion prevention systems are placed in-line and are able to actively prevent/block intrusions that are detected. More specifically, IPS can take such actions as sending an alarm, dropping the malicious packets, resetting the connection and/or blocking the traffic from the offending IP address. An IPS can also correct Cyclic Redundancy Check (CRC) errors, unfragment packet streams, prevent TCP sequencing issues, and clean up unwanted transport and network layer options.

Classifications

Intrusion prevention systems can be classified into four different types:

1. Network-based intrusion prevention system (NIPS): monitors the entire network for suspicious traffic by analyzing protocol activity.
2. Wireless intrusion prevention systems (WIPS): monitor a wireless network for suspicious traffic by analyzing wireless networking protocols.
3. Network behavior analysis (NBA): examines network traffic to identify threats that generate unusual traffic flows, such as distributed denial of service (DDoS) attacks, certain forms of malware and policy violations.
4. Host-based intrusion prevention system (HIPS): an installed software package which monitors a single host for suspicious activity by analyzing events occurring within that host.

Detection methods

The majority of intrusion prevention systems utilize one of three detection methods: signature-based, statistical anomaly-based, and stateful protocol analysis.

1. Signature-Based Detection: Signature based IDS monitors packets in the Network and compares with pre-configured and pre-determined attack patterns known as signatures.
2. Statistical anomaly-based detection: A statistical anomaly-based IDS determines the normal network activity —like what sort of bandwidth is generally used, what protocols are used, what ports and devices generally connect to each other— and alerts the administrator or user when traffic is detected which is anomalous (not normal).
3. Stateful Protocol Analysis Detection: This method identifies deviations of protocol states by comparing observed events with “predetermined profiles of generally accepted definitions of benign activity.”

See also

• Deviations of Protocol States
• Intrusion Detection System (IDS)
• Denial-of-service attack
• Host-based intrusion detection (HIDS)
• Network intrusion detection system
• Real-time adaptive security
• Software-defined protection
• Bypass switch

External links

• Common vulnerabilities and exposures (CVE) by product
• NIST SP 800-83, Guide to Malware Incident Prevention and Handling
• NIST SP 800-94, Guide to Intrusion Detection and Prevention Systems (IDPS)
• Study by Gartner "Magic Quadrant for Network Intrusion Prevention System Appliances"