Most
packet filters will not produce logs that are usable without extensive analysis and independent compilation.
Unlike traditional firewalls that act as
packet filters at the IP layer, a significant problem today is the data that is sent over the IP layer inside the filtered packet.
"We find changing parameters, such as proxies and
packet filters, very intuitive.
In addition to these security services, further security functionality, e.g.,
packet filters, deep packet inspection, or application-level gateways, can be integrated into the controller.
This approach to policy remediation may have worked when DEC developed the first
packet filters in 1988 and AT&T went on to develop stateful filtering technologies some two years later, but not anymore.
The application gateways act in a much more sophisticated way than
packet filters and circuit gateways which decide depending on the header data whether to let packet in or block it.