Chapter 7

anomaly-based monitoring
A monitoring technique used by an intrusion detection system (IDS) that creates a baseline of normal activities and compares actions against the baseline. Whenever there is a significant deviation from this baseline, an alarm is raised.
application-aware firewall
A firewall that can identify the applications that send packets through the firewall and then make decisions about the applications.
application-aware IDS
A specialized intrusion detection system (IDS) that is capable of using “contextual knowledge” in real time.
application-aware IPS
An intrusion prevention system (IPS) that knows information such as the applications that are running as well as the underlying operating systems.
application-aware proxy
A special proxy server that knows the application protocols that it supports.
behavior-based monitoring
A monitoring technique used by an IDS that uses the normal processes and actions as the standard and compares actions against it.
content inspection
Searching incoming web content to match keywords.
defense in depth
A defense that uses multiple types of security devices to protect a network. Also called layered security.
demilitarized zone (DMZ)
A separate network that rests outside the secure network perimeter: untrusted outside users can access the DMZ but cannot enter the secure network.
firewall rules
A set of individual instructions to control the actions of a firewall.
heuristic monitoring
A monitoring technique used by an intrusion detection system (IDS) that uses an algorithm to determine if a threat exists.
host-based intrusion detection system (HIDS)
A software-based application that runs on a local host computer that can detect an attack as it occurs.
intrusion detection system (IDS)
A device that detects an attack as it occurs.
layered security
A defense that uses multiple types of security devices to protect a network. Also called defense in depth.
load balancer
A dedicated network device that can direct requests to different servers based on a variety of factors.
malware inspection
Searching for malware in incoming web content.
network access control (NAC)
A technique that examines the current state of a system or network device before it is allowed to connect to the network.
network address translation (NAT)
A technique that allows private IP addresses to be used on the public Internet.
network intrusion detection system (NIDS)
A technology that watches for attacks on the network and reports back to a central device.
network intrusion prevention system (NIPS)
A technology that monitors network traffic to immediately react to block a malicious attack.
protocol analyzer
Hardware or software that captures packets to decode and analyze their contents.
proxy server
A computer or an application program that intercepts user requests from the internal secure network and then processes those requests on behalf of the users.
remote access
Any combination of hardware and software that enables remote users to access a local internal network.
reverse proxy
A computer or an application program that routes incoming requests to the correct server.
router
A device that can forward packets across computer networks.
signature-based monitoring
A monitoring technique used by an intrusion detection system (IDS) that examines network traffic to look for well-known patterns and compares the activities against a predefined signature.
subnetting (subnet addressing)
A technique that uses IP addresses to divide a network into network, subnet, and host.
switch
A device that connects network segments and forwards only frames intended for that specific device or frames sent to all devices.
Unified Threat Management (UTM)
Network hardware that provides multiple security functions.
URL filtering
Restricting access to unapproved websites.
virtual LAN (VLAN)
A technology that allows scattered users to be logically grouped together even though they may be attached to different switches.
virtual private network (VPN)
A technology that enables use of an unsecured public network as if it were a secure private network.
VPN concentrator
A device that aggregates VPN connections.
web application firewall
A special type of application-aware firewall that looks at the applications using HTTP.
web security gateway
A device that can block malicious content in real time as it appears (without first knowing the URL of a dangerous site).