Which mode allows a network interface controller to pass all traffic to the CPU?

• A. Normal mode
• B. Promiscuous mode
• C. Monitor mode
• D. Promiscuous port

Answer: (B)

Promiscuous mode is the configuration that makes the network interface pass all traffic it sees to the CPU, regardless of the destination address. In normal mode, the NIC filters and delivers only frames addressed to its own MAC, so traffic from other devices isn’t seen by the OS or sniffing tools. Enabling promiscuous mode allows packet-capture software like Wireshark to inspect every frame on the segment, which is essential for network analysis, troubleshooting, and security assessments. Monitor mode, while related for wireless adapters, operates in a different context to capture wireless frames, and promiscuous port isn’t a standard NIC mode.