intrusion detection system Last modified: Friday, December 13, 2002
An intrusion detection system (IDS) inspects all inbound and outbound network activity and identifies suspicious patterns that may indicate a network or system attack from someone attempting to break into or compromise a system. There are several ways to categorize an IDS: misuse detection vs. anomaly detection: in misuse detection, the IDS analyzes the information it gathers and compares it to large databases of attack signatures. Essentially, the IDS looks for a specific attack that has already been documented. Like a virus detection system, misuse detection software is only as good as the database of attack signatures that it uses to compare packets against. In anomaly detection, the system administrator defines the baseline, or normal, state of the network’s traffic load, breakdown, protocol, and typical packet size. The anomaly detector monitors network segments to compare their state to the normal baseline and look for anomalies. network-based vs. host-based systems: in a network-based system, or NIDS, the individual packets flowing through a network are analyzed. The NIDS can detect malicious packets that are designed to be overlooked by a firewall’s simplistic filtering rules. In a host-based system, the IDS examines at the activity on each individual computer or host. passive system vs. reactive system: in a passive system, the IDS detects a potential security breach, logs the information and signals an alert. In a reactive system, the IDS responds to the suspicious activity by logging off a user or by reprogramming the firewall to block network traffic from the suspected malicious source. Though they both relate to network security, an IDS differs from a firewall in that a firewall looks out for intrusions in order to stop them from happening. The firewall limits the access between networks in order to prevent intrusion and does not signal an attack from inside the network. An IDS evaluates a suspected intrusion once it has taken place and signals an alarm. An IDS also watches for attacks that originate from within a system.
•E-mail this definition to a colleague• Sponsored listings AT&T Enterprise Business Solutions - Find Out How AT&T Can Help Make Your Collaboration Easier For Less With Our Enterprise Solutions. Network Security Software Directory - Compare intrusion detection software using Capterra's free, comprehensive directory. Network Intrusion Detection (IDS) Software - Business technology search site offering software, service, reseller and hardware information on thousands of IT solutions. For internet.com pages about intrusion detection system . Also check out the following links! eSecurity Planet  A resource for daily information on e-security targeted to IT managers. The site provides users with information from a variety of sources, including experts at security product and services firms, and the consultants who follow the security industry. An Overview of Intrusion Detection Systems A white paper from Xinetica Ltd. Deploying an Effective Intrusion Detection System Not surprisingly, as the Internet grows at a mind-boggling pace, so does the incidence of documented unlawful attacks on corporate resources. Intrusion Detection FAQs From the SANS Institute. Intrusion Detection, Theory and Practice This article gives an overview of several types of intrusion detection systems, and introduces the reader to some of the concepts and practices involved in intrusion detection. Security Wars: Can Intrusion Detection Even the Score? Are IDS capabilities keeping up with intrusion attacks? SecurityTracker.com Information on the latest security vulnerabilities, free SecurityTracker Alerts, and customized vulnerability notification services. Sponsored listings Intrusion Detection Plan - Intrusion Detection and Prevention, Key Decisions In Planning. Things to Know Before Implementation. Download Free Report from Info-Tech. Enterprise Intrusion Detection Hardware - Carrier-grade Intrusion Detection. Behavior-based, self-learning. Download a white paper now! Network Intrusion Detection Systems - Read must-knows about network access control. Free whitepaper. Cisco 4210 IDS Series - Buys and sells refurbished, new, and used Cisco 4210 Intrusion Detection Systems with a 1-year warranty on all refurbished Cisco.	Security Software access CERT/CC crack cracker defacement DoS attack geek honeypot IP spoofing phreaking port scanning programmer quarantine sniffer Give Us Your Feedback Other Network Devices intrusion detection system Products Shop by Top Models: Cisco Intrusion Detection System Module (WS-X6381-IDS=) Network Monitoring Device 3 store offers from $149 - $3656 Cisco Intrusion Detection System Module 2 - Control processor (ws-svc-ids2bunk) Control Processor 6 store offers from $8499 - $27999 Cisco Intrusion Detection System 4215 Sensor (IDS-4215-K9) Network Monitoring Device 1 store offers from $5198 - $5198 Cisco Intrusion Detection System 4235 Sensor (IDS-4235-K9) Network Monitoring Device 3 store offers from $980 - $4596 Cisco Intrusion Detection System Network Module (NM-CIDS-K9=) Control Processor 4 store offers from $2077 - $2171