In computing, a firewall is a piece of
hardware and/or software which functions in a networked
environment to prevent some communications forbidden by
the security policy. A firewall has the basic task of
controlling traffic between different zones of trust.
Typical zones of trust include the Internet (a zone with
no trust) and an internal network (a zone with high trust).
The ultimate goal is to provide controlled connectivity
between zones of differing trust levels through the enforcement
of a security policy and connectivity model based on the
least privilege principle.
Firewalls are one of the best ways to protect
your computer from security threats.
You can often find firewalls at a discount eBay
. A software store may have
gotten surplus copies of firewall software or wish to reduce
their firewall inventory due to an updated version and will
sell new copies of firewalls at a reduced cost. Before you
bid on an auction, make sure that the firewall product says
the product is "new and in a retail box".
Following are firewall software auctions on eBay
.