Symantec 460R - Gateway Security Administrator's Manual page 169

DES (Data Encryption A widely-used method of data encryption using a private (secret) key that was judged so difficult to break by the U.S.
Standard)
government that it was restricted for exportation to other countries. There are 72,000,000,000,000,000 (72
quadrillion) or more possible encryption keys that can be used. For each given message, the key is chosen at random
from among this enormous number of keys. Like other private key cryptographic methods, both the sender and the
receiver must know and use the same private key.
DHCP (Dynamic Host A method of automatically serving IP addresses and other network settings to receiving hosts that contain a DHCP
Configuration
client. This eliminates having to manually assign IP addresses and other settings to hosts on a network. Most
Protocol)
modern OSs have a DHCP client.
dial To initiate a connection using a LAN, modem, or direct connection, regardless of whether actual dialing is involved.
Diffie-Hellman (DH) A cryptographic technique that enables sending and receiving parties to exchange public keys in a manner that
derives a shared, secret key at both ends. Different strengths are available and are referred to as Group 1, Group 2,
and Group 5 (and higher). DH is used as part of VPN negotiations to create new keys. See also Perfect Forward
Secrecy.
disabled A status that indicates that a program, job, policy, or scan is not available. For example, if scheduled scans are
disabled, a scheduled scan does not execute when the date and time specified for the scan is reached.
DNS (Domain Name System) A hierarchical system of host naming that groups TCP/IP hosts into categories. For example, in the Internet naming
scheme, names with .com extensions identify hosts in commercial businesses. See also DNS server.
DNS server A repository of addressing information for specific Internet hosts. Name servers use the Domain Name System (DNS)
to map IP addresses to Internet hosts. See also DNS.
domain A group of computers or devices that share a common directory database and are administered as a unit. On the
Internet, domains organize network addresses into hierarchical subsets. For example, the .com domain identifies
host systems that are used for commercial business.
domain entity A group of computers sharing the network portion of their host names, for example, symantec.com. Domain entities
are registered within the Internet community. Registered domain entities end with an extension such as .com, .edu,
or .gov or a country code such as .jp (Japan).
download To transfer data from one computer to another, usually over a modem or network. Usually refers to the act of
transferring a file from the Internet, a bulletin board system (BBS), or an online service to one's own computer. See
also upload.
dynamic DNS
The ability to automatically update a DNS server when an IP address is automatically assigned or changed (typically
from an ISP using DSL or cable) to a network gateway. Whenever an assigned IP address changes, the domain name
(www.mybranchoffice.com for example) is immediately updated by the gateway to the new IP address. This enables
lower-cost dynamic IP Internet accounts for services like VPN or server hosting where static IP accounts are either
unavailable or cost-prohibitive.
email server An application that controls the distribution and storage of email messages.
enabled A status that indicates that a program, job, policy, or scan is available. For example, if scheduled scans are enabled,
any scheduled scan will execute when the date and time specified for the scan is reached.
encryption
A method of scrambling or encoding data to prevent unauthorized users from reading or tampering with the data.
Only those who have access to a password or key can decrypt and use the data. The data can include messages, files,
folders, or disks.
Ethernet
A local area network (LAN) protocol developed by Xerox Corporation in cooperation with DEC and Intel in 1976.
Ethernet uses a bus or star topology and supports data transfer rates of 100 Mbps.
event
A message that is generated by a product to indicate that something has happened.
event class A predefined event category that is used for sorting reports and configuring alerts.
Event Collector An application that collects events from security products, processes them, and places them in the SESA DataStore.
event forwarding The process by which an administrator forwards events to another SESA Manager. Event forwarding includes the
ability to filter events selectively before forwarding.
Glossary 169