 
Our tests
have showed that among advanced firewall applications, ActiveDefender
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What does a Firewall
Do?
An Internet firewall examines all traffic
routed between your network and the Internet to see if it meets certain
criteria. If it does, it is routed between the networks, otherwise it
is stopped. A network firewall filters both inbound
and outbound traffic. It can also manage public access to private networked
resources such as host applications. It can be used to log all attempts
to enter the private network and trigger alarms when hostile or unauthorized
entry is attempted. Firewalls can filter packets based on their source,
destination addresses and port numbers. This is known as address filtering.
Firewalls can also filter specific types of network traffic. This is
also known as protocol filtering because the decision to forward or
reject traffic is dependant upon the protocol used, for example HTTP,
ftp or telnet. Firewalls can also filter traffic by packet attribute
or state.
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