SnapGear 1.7.8 manual Terminology, Term Meaning

Terminology

This section explains terms that are commonly used in this document.

Term	Meaning
ADSL	Asymmetric Digital Subscriber Line. A technology allowing high-
	speed data transfer over existing telephone lines. ADSL supports
	data rates between 1.5 and 9 Mb/s when receiving data and between
	16 and 640 Kb/s when sending data.
BOOTP	Bootstrap Protocol. A protocol that allows a network user to
	automatically receive an IP address and have an operating system
	boot without user interaction. BOOTP is the basis for the more
	advanced DHCP.
DHCP	Dynamic Host Configuration Protocol. A communications protocol
	that assigns IP addresses to computers when they are connected to
	the network.
DNS	Domain Name System that allocates Internet domain names and
	translates them into IP addresses. A domain name is a meaningful
	and easy to remember name for an IP address.
DUN	Dial Up Networking.
Ethernet	A physical layer protocol based upon IEEE standards.
Extranet	A private network that uses the public Internet to securely share
	business information and operations with suppliers, vendors,
	partners, customers, or other businesses. Extranets add external
	parties to a company’s intranet.
Failover	A method for detecting that the main Internet connection (usually a
	broadband connection) has failed and the SnapGear apliance cannot
	communicate with the Internet. If this occurs, the SnapGear appliance
	automatically moves to a lower speed, secondary Internet
	connection.
Fall-forward	A method for shutting down the failover connection when the main
	Internet connection can be re-established.
Firewall	A network gateway device that protects a private network from users
	on other networks. A firewall is usually installed to allow users on an
	intranet access to the public Internet without allowing public Internet
	users access to the intranet.
Gateway	A machine that provides a route (or pathway) to the outside world.
Hub	A network device that allows more than one computer to be
	connected as a LAN, usually using UTP cabling.
IDB	Intruder Detection and Blocking. A feature of your SnapGear VPN
	appliance that detects connection attempts from intruders and can
	also optionally block all further connection attempts from the
	intruder’s machine.
Internet	A worldwide system of computer networks - a public, cooperative,
	and self-sustaining network of networks accessible to hundreds of

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Introduction