Which firewall type below uses a dynamic state table to inspect the content of packets?

A.
An application-level firewall

B.
A stateful-inspection firewall

C.
A circuit-level firewall

D.
A packet-filtering firewall

Explanation:
A stateful-inspection firewall intercepts incoming packets at the Network level, then uses an
Inspection Engine to extract state-related information from upper layers. It maintains the
information in a dynamic state table and evaluates subsequent connection attempts. * packetfiltering firewall is the simplest type of firewall commonly implemented on routers. It operates at the
Network layer and offers good performance but is the least secure. * application-level firewall or
application-layer gateway, is more secure because it examines the packet at the application layer,
but at the expense of performance. * circuit-level firewall, is similar to the application-level firewall
in that it functions as a proxy server, but differs in that special proxy application software is not
needed. Sources: Hacker Proof by Lars Klander (Jamsa Press, 1997) and Checkpoint Firewall-1
Stateful Inspection Technology (www.checkpoint.com).