Stateful packet inspection is a security technology used by which of the following devices?

A.
Unmanaged switch

B.
Hardware firewall

C.
Bridge

D.
IDS

Explanation:

With Stateful Packet Inspection (SPI), every time a packet is sent out of the computer, the firewall
keeps track of it. When a packet comes back to the firewall, the firewall can tell whether or not the
in-bound packet is a reply to the packet that was sent out.This way, the firewall can handle most
network traffic safely without a complex configuration of firewall rules.