Security Solutions

A-23
Appendix A: Glossary
V
virus A computer program that can copy itself and damage a computer system. A
virus cannot self-propagate as a worm can but is spread via infected removable
media (floppy disks, zip drives, USB drives) or by sending it over a network.
Viruses can be programmed to do all kinds of damage, such as erasing hard
drives, deleting files, or corrupting executables, or they can be relatively
benign (showing text or a graphic), but even the benign viruses use up
computer resources such as hard drive space, memory, and processor cycles.
Like biological viruses, they can modify themselves upon replication to avoid
easy detection.
VLAN Virtual Local Area Network. A standard that enables network administrators
to group end-users by logical function rather than by physical location. VLANs
are created on switches to segment networks into smaller broadcast domains,
enhance network security, and simplify network management. For more
information, see IEEE 802.1Q at http://www.ieee802.org/1/pages/
802.1Q.html.
VoIP Voice over Internet Protocol. Also called “IP telephony,” the routing of voice
conversations via packets over an IP network such as the Internet.
VPN Virtual Private Network. A network that is tunneled through another network,
often a connection to a private network over the Internet. The tunneling is
usually achieved through authentication and encryption.
VSA Vendor-Specific Attributes. RADIUS attributes that the manufacturers of
RADIUS solutions can add without disturbing the existing functions of the
protocol.
W
war driver Someone who uses a directional antenna to pick up signals from a company’s
WLAN. War drivers are so called because they often drive along the road to see
which signals they can pick up. They often analyze wireless packets to obtain
information on the network’s structure and security protocols, and they can
sometimes connect to a WLAN if the security settings are not strong enough.
Web-Auth A method for authenticating end-users that does not require a client utility on
the endpoints. The NAS redirects end-users to a Web page in which the end-
users submit their credentials. The NAS retrieves the credentials and submits
them to an authentication server.