Internet RFCs and STDs ICSSCADA Practice Questions (Page 3)

Questions 11–15

1. 11application · medium

   An ICS network uses a protocol that relies on UDP for time synchronization. The engineer notices that the time stamps are drifting. Which RFC-defined protocol should the engineer check to ensure the implementation follows the standard?

   • ARFC 768 (UDP)
   • BRFC 793 (TCP)
   • CRFC 5905 (NTP)
   • DRFC 791 (IP)
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2. 12application · medium

   A network administrator is evaluating a new protocol for a smart grid deployment. The protocol is currently described in an Internet-Draft. The vendor claims it will become an RFC soon. What is the most accurate statement about the Internet-Draft's status?

   • AIt is an Internet Standard because it has been published by the IETF.
   • BIt is a working document that may change or expire and has no formal standard status.
   • CIt is a Draft Standard and is stable enough for production use.
   • DIt is already a Proposed Standard and can be implemented with confidence.
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4. 13application · medium

   An ICS engineer is troubleshooting a serial-to-Ethernet gateway that connects legacy PLCs to a SCADA server. The gateway uses Modbus/TCP, and the engineer notices that the SCADA server sometimes receives duplicate or out-of-order responses. The engineer wants to ensure reliable, ordered delivery of Modbus/TCP traffic without changing the application protocol. Which RFC-defined protocol should the engineer verify is correctly configured on both the gateway and the SCADA server?

   • AICMP (RFC 792)
   • BARP (RFC 826)
   • CTCP (RFC 9293)
   • DUDP (RFC 768)
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5. 14application · medium

   A SCADA network uses a protocol that is defined by an RFC with the status 'Internet Standard.' The engineer is planning to upgrade the protocol stack to a newer version that is only available as a Proposed Standard. What should the engineer consider?

   • AThe Proposed Standard is guaranteed to be backward compatible.
   • BThe Proposed Standard may change before becoming a full Internet Standard, so the upgrade should be carefully evaluated.
   • CThe Proposed Standard is more mature than the Internet Standard.
   • DThe Internet Standard is automatically obsoleted by the Proposed Standard.
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6. 15application · medium

   A control system engineer is reviewing a vendor's protocol documentation and finds that a protocol used in the SCADA network is described as 'Internet Standard' with an STD number. The engineer wants to verify the exact technical specification. What is the most reliable way to find the current specification?

   • ASearch for the most recent Internet-Draft with the same protocol name.
   • BCheck the RFC Editor's list of Proposed Standards.
   • CUse the vendor's documentation as the authoritative source.
   • DLook up the STD number in the RFC Index to find the current RFC(s) associated with it.
   Reveal Solution Discussion Select an answer first