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ZyXEL Communications ZYWALL10 User Manual

Page 257

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ZyWALL 10 Internet Security Gateway

Glossary of Terms

S

same as your Ethernet address.) The MAC layer frames data for transmission over the
network, then passes the frame to the physical layer interface where it is transmitted as
a stream of bits.

Name Resolution

The allocation of an IP address to a host name. See DNS

NAT

Network Address Translation is the translation of an Internet Protocol address used
within one network to a different IP address known within another network - see also
SUA.

NDIS

Network Driver Interface Specification is a Windows specification for how
communication protocol programs (such as TCP/IP) and network device drivers should
communicate with each other.

NetBIOS

Network Basic Input / Output System. NetBIOS is an extension of the DOS BIOS that
enables a PC to connect to and communicate with a LAN.

Network

Any time you connect 2 or more computers together so that they can share resources,
you have a computer network. Connect 2 or more networks together and you have an
internet.

NIC

Network Interface Card. A board that provides network communication capabilities to
and from a computer system. Also called an adapter.

Node

Any single computer connected to a network

PAC

The box that calls/answers the phone call and relays the PPP frames to the PNS. A
PAC must have IP and dial-up capability.

Packet Filter

A filter that scans packets and decides whether to let them through.

PAP

Password Authentication Protocol PAP is a security protocol that requires users to enter
a password before accessing a secure system. The user’s name and password are sent
over the wire to a server, where they are compared with a database of user account
names and passwords. This technique is vulnerable to wiretapping (eavesdropping)
because the password can be captured and used by someone to log onto the system.

Password Cracker

A program that uses a dictionary of words, phrases, names, etc. to guess a password.

Password
encryption

A system of encrypting electronic files using a single key or password. Anyone who
knows the password can decrypt the file.

Password
Shadowing

The encrypted password is not visible in the password file but stored in a shadow file
that is only readable by root. This prevents brute force attacks on the encrypted field to
guess the password. see e.g.: http://whatis.com/shadowpa.htm

Penetration

Gaining access to computers or networks by bypassing security programs and
passwords.

Phreaking

Breaking into phone or other communication systems. Phreaking sites on the Internet
are popular among crackers and other criminals

Ping Attack

An attack that slows down the network until it is unusable. The attacker sends a "ping"
command to the network repeatedly to slow it down. See also Denial of Service.

Pirate

Someone who steals or distributes software without paying the legitimate owner for it.