User guide

User Guide 169
default
A predefined setting that is built into a program and is used when an alternative
setting is not specified.
default packet handling
The practice of automatically and temporarily blocking hosts that originate
probes and attacks against a network.
denial of service attack (DoS)
A way of monopolizing system resources so that other users are ignored. For
example, someone could Finger an unsecured host continuously so that the
system is incapable of running or executing other services.
DES (Data Encryption Standard)
A block-oriented cipher that encrypts blocks of 64 bits. The encryption is
controlled by a key of 56 bits. See also
Triple DES .
descending
A method of ordering a group of items from highest to lowest, such as from Z to
A.
device
Networking equipment such as a hub, switch, bridge, or router.
DHCP (Dynamic Host Configuration Protocol)
A means of dynamically allocating IP addresses to devices on a network.
DHCP server
A device that automatically assigns IP addresses to network computers from a
defined pool of numbers.
dialog box
A box that displays additional options when a command is chosen from a menu.
dial-up connection
A connection between a remote computer and a server using software, a
modem, and a telephone.
dictionary attack
An attack that attempts to reveal a password by trying logical combinations of
words.
Diffie-Hellman
A mathematical technique for securely negotatiating secret keys over a public
medium.
digital signature
An electronic identification of a person or thing created by using a public key
algorithm. Intended to verify to a recipient the integrity of data and identity of
the sender of the data.