Technology Introduction; Introduction To Broadband Router Technology; Introduction To Firewalls - D-Link DIR-100 User Manual

Section 1 - Product Overview

Technology Introduction

Introduction to Broadband Router Technology

A router is a device that forwards data packets from a source to a destination. Routers forward data packets using IP addresses and
not a MAC address. A router will forward data from the Internet to a particular computer on your LAN.
The information that makes up the Internet gets moved around using routers. When you click on a link on a web page, you send a
request to a server to show you the next page. The information that is sent and received from your computer is moved from your
computer to the server using routers. A router also determines the best route that your information should follow to ensure that the
information is delivered properly.
A router controls the amount of data that is sent through your network by eliminating information that should not be there. This
provides security for the computers connected to your router, because computers from the outside cannot access or send information
directly to any computer on your network. The router determines which computer the information should be forwarded to and sends
it. If the information is not intended for any computer on your network, the data is discarded. This keeps any unwanted or harmful
information from accessing or damaging your network.

Introduction to Firewalls

A firewall is a device that sits between your computer and the Internet that prevents unauthorized access to or from your network.
A firewall can be a computer using firewall software or a special piece of hardware built specifically to act as a firewall. In most
circumstances, a firewall is used to prevent unauthorized Internet users from accessing private networks or corporate LAN's and
Intranets.
A firewall watches all of the information moving to and from your network and analyzes each piece of data. Each piece of data is
checked against a set of criteria that the administrator configures. If any data does not meet the criteria, that data is blocked and
discarded. If the data meets the criteria, the data is passed through. This method is called packet filtering.
A firewall can also run specific security functions based on the type of application or type of port that is being used. For example,
a firewall can be configured to work with an FTP or Telnet server. Or a firewall can be configured to work with specific UDP or TCP
ports to allow certain applications or games to work properly over the Internet.
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