Glossary
GL-15
Cisco Intrusion Prevention System Sensor CLI Configuration Guide for IPS 7.2
OL-29168-01
P
P2P
Peer-to-Peer. P2P networks use nodes that can simultaneously function as both client and server for the
purpose of file sharing.
packet
Logical grouping of information that includes a header containing control information and (usually)
user data. Packets most often are used to refer to network layer units of data. The terms datagram,
frame, message, and segment also are used to descri be logical information groupings at various layers
of the OSI reference model and in various technology circles.
PAgP
Port Aggregation Control Protocol. PAgP aids in the automatic creation of EtherChannel links by
exchanging PAgP packets between LAN ports. It is a Cisco-proprietary protocol.
PAM
Software module that provides AAA functionality to applications.
PAP
Password Authentication Protocol. Most commonly used RADIUS messaging protocol.
passive
fingerprinting
Act of determining the OS or services available on a system from passive observation of network
interactions.
Passive OS
Fingerprinting
The sensor determines host operating systems by inspecting characteristics of the packets exchanged
on the network.
PASV Port Spoof
An attempt to open connections through a firewall to a protected FTP server to a non-FTP port. This
happens when the firewall incorrectly interprets an FTP 227 passive command by opening an
unauthorized connection.
PAT
Port Address Translation. A more restricted translation scheme than NAT in which a single IP address
and different ports are used to represent the hosts of a network.
patch release
Release that addresses defects identified in the update (minor, major, or service pack) binaries after a
software release (service pack, minor, or major update ) has been released.
PAWS
Protection Against Wrapped Sequence. Protection against wrapped sequence numbers in high
performance TCP networks. See RFC 1323.
PCI
Peripheral Component Interface. The most common peripheral expansion bus used on Intel-based
computers.
PDU
protocol data unit. OSI term for packet. See also BPDU and packet.
PEP
Cisco Product Evolution Program. PEP is the UDI information that consists of the PID, the VID, and
the SN of your sensor. PEP provides hardware version and serial number visibility through electronic
query, product labels, and shipping items.
PER
packed encoding rules. Instead of using a generic style of encoding that encodes all types in a uniform
way, PER specializes the encoding based on the date type to generate much more compact
representations.
PFC
Policy Feature Card. An optional card on a Catalyst 6000 supervisor engine that supports VACL packet
filtering.
PID
Product Identifier. The orderable product identifier that is one of the three parts of the UDI. The UDI
is part of the PEP policy.