Which firewall has minimal performance impact while still performing full packet inspection at every layer?

• A. Next Generation Firewall
• B. Kernel Proxy
• C. Packet-Filtering Firewall
• D. Unified Threat Management

Answer: (B)

Focusing on doing deep checks across all layers while keeping speed, this approach runs the proxy logic inside the kernel. That means packets can be examined in the fastest path of the system, with less overhead from switching between kernel and user space. The kernel handles the inspection across network, transport, and application layers efficiently, enforcing policies and filtering decisions as the data moves through, which keeps performance impact minimal.

In contrast, other options either don’t perform full-depth, cross-layer inspection or they introduce more processing work. A packet-filtering firewall mainly checks headers and doesn't deeply inspect payloads across every layer. A next-generation firewall adds sophisticated application-aware checks, which increases processing load and latency. Unified threat management combines many security services, typically reducing throughput due to the breadth of features.