Cisco IPS-4240-K9 - Intrusion Protection Sys 4240 Installation Manual page 173

demilitarized zone. A separate network located in the neutral zone between a private (inside) network
DMZ
and a public (outside) network.
Denial of Service. An attack whose goal is just to disrupt the operation of a specific system or network.
DoS
Distributed Denial of Service. An attack in which a multitude of compromised systems attack a single
DDoS
target, thereby causing denial of service for users of the targeted system. The flood of incoming
messages to the target system essentially forces it to shut down, thereby denying service to the system
to legitimate users.
Domain Name System. An Internet-wide hostname to IP address mapping. DNS enables you to convert
DNS
human-readable names into the IP addresses needed for network packets.
dynamic random-access memory. RAM that stores information in capacitors that must be refreshed
DRAM
periodically. Delays can occur because DRAMs are inaccessible to the processor when refreshing their
contents. However, DRAMs are less complex and have greater capacity than SRAMs.
E
Traffic leaving the network.
egress
Application of a specific algorithm to data to alter the appearance of the data making it
encryption
incomprehensible to those who are not authorized to see the information.
A component of the sensor designed to support many signatures in a certain category. Each engine has
engine
parameters that can be used to create signatures or tune existing signatures.
Large and diverse network connecting most major points in a company or other organization. Differs
enterprise network
from a WAN in that it is privately owned and maintained.
Used in regular expression. A character can be represented as its hexadecimal value, for example, \x61
escaped expression
equals 'a,' so \x61 is an escaped expression representing the character 'a.'
electrostatic discharge. Electrostatic discharge is the rapid movement of a charge from one object to
ESD
another object, which produces several thousand volts of electrical charge that can cause severe damage
to electronic components or entire circuit card assemblies.
An IPS message that contains an alert, a block request, a status message, or an error message.
event
One of the components of the IPS.
Event Server
One of the components of the IPS. A fixed-size, indexed store used to store IPS events.
Event Store
The XML entity written to the Event Store that represents an alert.
evIdsAlert
F
A signature is not fired when offending traffic is detected.
false negative
Normal traffic or a benign action causes a signature to fire.
false positive
78-16124-01
Installing Cisco Intrusion Prevention System Appliances and Modules 5.0
Glossary
GL-5