Glossary
GL-7
Cisco Intrusion Prevention System Sensor CLI Configuration Guide for IPS 7.2
OL-29168-01
DIMM
Dual In-line Memory Modules.
DMZ
demilitarized zone. A separate network located in the neutral zone between a private (inside) network
and a public (outside) network.
DNS
Domain Name System. An Internet-wide hostname to IP address mapping. DNS enables you to convert
human-readable names into the IP addresses needed for network packets.
DoS
Denial of Service. An attack whose goal is just to disrupt the operation of a specific system or network.
DRAM
dynamic random-access memory. RAM that stores information in capacitors that must be refreshed
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.
DTE
Data Terminal Equipment. Refers to the role of a device on an RS-232C connection. A DTE writes data
to the transmit line and reads data from the receive line.
DTP
Dynamic Trunking Protocol. A Cisco proprietary protocol in the VLAN group used for negotiating
trunking on a link between two devices and for negotiating the type of trunking encapsulation (ISL or
802.1q) to be used.
E
ECLB
Ether Channel Load Balancing. Lets a Catalyst switch split traffic flows over different physical paths.
egress
Traffic leaving the network.
encryption
Application of a specific algorithm to data to alter the appearance of the data making it
incomprehensible to those who are not authorized to see the information.
engine
A component of the sensor designed to support many signatures in a certain category. Each engine has
parameters that can be used to create signatures or tune existing signatures.
enterprise network
Large and diverse network connecting most major points in a company or other organization. Differs
from a WAN in that it is privately owned and maintained.
escaped expression
Used in regular expression. A character can be represented as its hexadecimal value, for example, \x61
equals ‘a,’ so \x61 is an escaped expression representing the character ‘a.’
ESD
electrostatic discharge. Electrostatic discharge is the rapid movement of a charge from one object to
another object, which produces several thousand volts of electrical charge that can cause severe damage
to electronic components or entire circuit card assemblies.
event
An IPS message that contains an alert, a block request, a status message, or an error message.
Event Store
One of the components of the IPS. A fixed-size, indexed store used to store IPS events.
evIdsAlert
The XML entity written to the Event Store that represents an alert.