Entercept falls into the category of an intrusion prevention system (IPS). In common with traditional host-based IDS, Entercept resides on the host itself, but it works at a much lower level than a normal HIDS system.
This solution provides a network-based IDS, real-time session monitoring and internet/email content blocking. eTrust Intrusion Detection can be installed in standalone mode, or it can be distributed on separate machines. The intrusion detection program installs as a service under Windows NT/2000. As usual, the monitoring interface is a NIC in promiscuous mode, and therefore the presence of the IDS is concealed from the attacker.
This solution is supplied as software, desktop or rack-mounted. Each network sensor is a separate appliance, handing high-availability, high-security 10/100 or gigabit monitored segments.Running on a hardened OS, based on Red Hat Linux, in a small installation it can be managed using a web-based interface, software or optionally as an appliance.
NetScreen uses multi-method detection (MMD) in its IDS appliance, which also includes intrusion prevention options. MMD integrates stateful signature analysis with the detection of protocol anomalies, traffic anomalies, IP spoofing, layer 2 and SYN-flood attacks. Plus, it includes detection of 'backdoor' exploits and a network honeypot. The NetScreen IDP-100 is rated at 200Mbits/sec throughput, offering a choice of eight Fast Ethernet or two separate gigabit monitoring ports.
This is a network-based IDS, supplied as an appliance. There are four versions of the NID-300 series - the difference being in the number and speed of the Ethernet interfaces. The top-of-the-range model has two 10/100Mbit and two gigabit network interfaces. One of these interfaces is always reserved for management, but the remainder can be used for monitoring. In this way, a single NID-300 can monitor load-balanced or failover WAN connections. By separating the management and monitoring interfaces, NID-300 can operate in stealth mode, as the monitoring interface does not respond to any network traffic or requests from any service on the monitored network.
RealSecure 7.0 is the result of the integration between RealSecure and the BlackICE NIDS sensor technology. It runs on a dedicated machine and acts as a NIPS sensor to monitor a network segment, looking for intrusions or suspicious activity. If an intrusion is suspected, it can respond by recording details of the event. It can notify the network administrator, reconfigure the firewall, or terminate the event.
StealthWatch employs a completely different approach to traditional IDS, based on signature recognition. Instead of looking for signatures, it 'learns' what kind of activity is normal on your network and looks for abnormal events. Behavior-based IDS has some advantages over signature-based IDS, because less processing power is required and previously unknown attacks can be detected.
This software network-based IDS product requires a dedicated machine running Solaris 8 on either Sun SPARC or Intel hardware. The hardware specification depends on the amount of traffic to be monitored, and gigabit monitoring interfaces are supported. We were supplied with a pre-installed system running on a Dell PowerEdge rack-mounted server - however, customers would have to provide their own hardware; prices quoted are for software only.
If a firewall is your first line of defense then an IDS should be your second. It's the burglar alarm of your vulnerability assessment tools. By Geoff Marshall