Introduction
Firewalls are used to monitor and control the inbound and
outbound traffic on the protected network. They have an ability to block
and allow the internal as well as external services within the network.
Before allowing access to the service, a firewall may also force the
client / user to pass through an authentication. Sometimes a firewall
can be also used in IPSEC tunnels as a platform. It monitors
security-related events.
