User guide

User Guide 161
APPENDIX B Glossary
This glossary contains a list of terms, abbreviations, and acronyms fre-
quently used when discussing networks, firewalls, and WatchGuard prod-
ucts.
access control
A method of restricting access to resources, allowing access only to privileged
entities.
active mode FTP
One of two ways an FTP data connection is made. In active mode, the FTP
server establishes the data connection. In passive mode, the client establishes the
connection. In general, FTP user agents use active mode and Web user agents
use passive mode.
activity light
An LED (light-emitting diode) that verifies that a piece of hardware is working,
communicating with the network, and transmitting data.
address learning
A method by which hubs, switches, and routers determine the unique address
number for each node on a network to enable accurate transmission to and
from each node.
Address Resolution Protocol (ARP)
A TCP/IP protocol used to convert an IP address into a physical address such as
an Ethernet address.