Introduction To Broadband Router Technology; Introduction To Firewalls - D-Link DI-704P User Manual

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 specif ic UDP or TCP ports to allow certain applications or games to
work properly over the Internet.
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