Specifications

Glossary
206 Equalizer Installation and Administration Guide
physical server A machine located on the internal network that provides services on specific IP
addresses and ports. See server and virtual web server. See also authoritative
name server, back-end server, name server, and proxy server.
piece An atom followed by a single *, +, or ?, or by a bound. See atom, branch, and
regular expression.
ping A program used to test reachability of destinations by sending them an ICMP
echo request and waiting for a reply. See echo and probe. See also CMP echo
request
port The abstraction used by Internet transport protocols to distinguish among
multiple simultaneous connections to a single destination host.
port number The number used to identify a service contact port, such as HTTP port 80.
primary Equalizer The primary unit that handles requests. If the primary Equalizer fails, the
backup unit replaces it. See also backup Equalizer and hot backup.
probe An action that obtains status information about a computer, network, or device.
See geographic probe and ping.
protocol A set of rules that govern adherence to a set of standards. See protocol stack.
protocol stack A layer of protocols that process network actions cooperatively and in tandem.
See protocol.
proxy server A utility, which is part of a firewall, that helps the regular tasks of managing
data transmittal from a network to the Internet and from the Internet to the
network. See also firewall.
quiesce To become quiet or more quiet than previously.
RADIUS Remote Authentication Dial-In User Service; a protocol that authorizes and
authenticates a user trying to link to a network or the Internet.
redirection The process of receiving input from or sending output to a different resource
than usual.
regular expression (RE) One or more non-empty branches, separated by pipe symbols
(|). An
expression matches anything that matches one of the branches. See atom,
branch and piece.
request packet A packet that contains information that requests a response. See packet and
response packet.
reserved network A network consisting of “phony” IP addresses, which are not registered and
cannot be made visible outside of the internal network.
resolution The process of interpreting all the messages between an IP address and a
domain name address.
response packet A packet that contains information that responds to a request. See packet and
request packet.
round robin The default load balancing policy which distributes requests equally among all
servers in a virtual cluster, without regard to static weights or adaptive load
balancing criteria. The first request received is routed to the first server in the
list, the second request to the second server, and so on. When the last server
is reached, the cycle starts again with the first server.
router A network device that facilitates the transmission (that is, routing) of messages.
routing table A database, which is static or dynamic, that contains a set of route addresses
and routing information familiar to the router. A human being enters and
updates the information in a static routing table; routers operate and constantly
update a dynamic routing table.
RST The reset command, which instructs a device to end a connection.