Firewall
Any
network that is connected to the Internet should pass communication
through a
firewall.
A firewall is a combination of hardware and software that prevents
unauthorized access to an internal network from outside. All
messages entering or leaving a network pass through the firewall,
which examines each message and blocks those that do not meet the
specified security criteria. A firewall filters out traffic that
should not pass between the Internet and your private network, such
as messages between two computers within your private network.
How
Does a Firewall Work?
A
firewall prevents direct communication between network and external
computers by routing communication through a proxy server located
outside of the network. The firewall determines if it is safe to let
a file pass to the network and from the network. A firewall is also
called a security-edge gateway.
Microsoft Proxy Server
Microsoft provides software that combines the features of a proxy
server and a firewall into a single product, Microsoft Proxy Server.
How
Does Microsoft Proxy Server Work?
Microsoft Proxy Server acts as a secure gateway between your LAN and
the Internet. A gateway enables two different networks to
communicate. Proxy Server provides a connection to the Internet for
your group, ivision, or your entire intranet. Proxy Server also
acts as a secure gateway and a firewall by allowing inbound access
from the Internet to your network. By using a Proxy Server gateway,
you can secure your network against intrusion. Proxy Server enables
you to make requests to the Internet and to receive information, but
it prevents unauthorized users from accessing your network. You can
configure Proxy Server to enable your workstations to communicate
with remote services on the Internet. To do this, you select the
appropriate hardware for Proxy Server, making sure that you have
adequate bandwidth for the Internet connection, and choose the level
of security at which you want to protect your LAN.