CyberCertPrepOT Security FundamentalsOT Fundamentals: Securing Industrial Control SystemsMEDIUMFree question
A passive sensor on the plant core switch lists HMIs and servers but no field devices on an RS-485 loop behind a protocol gateway. What explains the gap?
- A.The sensor drops Modbus RTU frames after a fixed hop count
- B.Serial frames do not cross the mirrored Ethernet port
- C.RS-485 devices publish encrypted beacons the sensor ignores
- D.Gateways strip device serial numbers before forwarding frames
Why B is correct
Traffic on a serial loop stays on the serial wire, and the gateway presents only its own Ethernet side to the switch. Devices behind it need another source such as a gateway configuration export or a physical walk-down.
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