Techniques Used in a Firewall
• Direction control
• Determines the direction in which particular service requests
may be initiated and allowed to flow through the firewall.
• User control:
• Controls access to a service according to which user is
attempting to access it.
• This feature is typically applied to users inside the firewall perimeter (local users). It may also be applied to incoming traffic from external users; the latter requires some form of secure authentication technology, such as is provided in IPsec.