Which device has multiple NICs and connects to two or more networks to increase efficiency and reliability of an IP network?

• A. DMZ
• B. Bastion Host
• C. Multi-homed Firewall
• D. Software Firewall

Answer: (C)

The device described is using multiple network interfaces to connect to more than one network, a setup known as multi-homing a firewall. By having separate NICs for different networks (for example, internal LAN, external Internet, and optionally a DMZ), the firewall can enforce distinct security policies on traffic between those networks and provide redundancy. If one link or interface fails, traffic can continue flowing through another path, improving reliability, and distributing load can improve performance.

Other options don’t fit this description as cleanly: a DMZ is a network zone, not a dedicated multi-network device; a Bastion Host is a hardened system exposed to the public network; and a Software Firewall is firewall software running on a host and isn’t inherently defined by having multiple NICs connecting separate networks.