CyberCertPrepOT Security FundamentalsOT Fundamentals: Network Architecture & ProtocolsEASYFree question
A maintenance team wants to know how a Modbus RTU frame on a serial line is checked for transmission errors. Which mechanism does the frame use?
- A.A 32-bit checksum placed in the MBAP header
- B.A parity bit negotiated by the TLS handshake
- C.A 16-bit CRC appended to each frame
- D.An HMAC appended to each frame by the master
Why C is correct
Modbus RTU frames end with a 16-bit CRC. There is no HMAC, the MBAP header belongs to Modbus TCP, and plain Modbus has no TLS handshake. A CRC catches noise but gives no protection against deliberate tampering.
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