SPI firewalls can conduct ________ inspection.

• A. Both A and B
• B. Stateful packet
• C. Static packet filtering
• D. Neither A nor B

Answer: (A)

Stateful Packet Inspection examines traffic with awareness of active connections. It keeps a state table of ongoing connections and checks each packet to ensure it belongs to a valid, allowed session, looking at details like IPs, ports, and flags to decide permit or deny.

Many SPI firewalls also perform static packet filtering as part of their rule set. Static filtering applies ACL-like rules to packets based on header fields without considering connection state, such as blocking traffic from a known bad IP or on disallowed ports.

Because an SPI firewall can use both stateful inspection and static filtering, the best description is that it can conduct both types of inspection. This combination lets the firewall first enforce straightforward access controls, then apply stateful checks to ensure packets participate in legitimate, established connections.

So the correct idea is that SPI firewalls can perform both stateful inspection and static packet filtering.