Components of TCP/IP Networks ICSSCADA Practice Questions (Page 2)

Questions 6–10

1. 6application · easy

   A small water treatment plant has a network with a single switch connecting 20 PLCs and an HMI. The plant manager wants to add a second HMI and a historian server. The network must remain simple and cost-effective. Which topology should the engineer recommend?

   • ARing topology with devices connected in a loop.
   • BStar topology with all devices connected to the existing switch.
   • CBus topology with a single backbone cable.
   • DMesh topology with multiple connections between devices.
   Reveal Solution Discussion Select an answer first
2. 7application · medium

   An engineer is capturing packets on a SCADA network and sees a frame with a source MAC address, source IP address, source TCP port 502, and a payload containing Modbus data. Which protocol stack is represented in this frame?

   • AEthernet, IP, and Modbus only
   • BEthernet, IP, UDP, and Modbus
   • CEthernet, IP, TCP, and Modbus
   • DIP, TCP, and Modbus only
   Reveal Solution Discussion Select an answer first
4. 8foundation · easy

   What is the primary function of a switch in a TCP/IP network?

   • ATo forward frames based on MAC addresses
   • BTo translate domain names to IP addresses
   • CTo route packets between different networks using IP addresses
   • DTo broadcast all incoming data to every connected device
   Reveal Solution Discussion Select an answer first
5. 9application · medium

   A SCADA engineer is troubleshooting a remote terminal unit (RTU) that sends periodic process measurements to a central historian. The RTU uses a connectionless protocol, and the historian occasionally misses samples. The engineer needs to confirm whether the missing samples are due to the transport protocol's characteristics. Which protocol behavior should the engineer examine?

   • ATCP's checksum validation causes it to discard packets silently without retransmission.
   • BTCP will retransmit lost segments but only if the receive window is set to zero.
   • CUDP uses a three-way handshake that can fail under high latency.
   • DUDP does not guarantee delivery, so dropped datagrams are not retransmitted.
   Reveal Solution Discussion Select an answer first
6. 10application · medium

   A network technician is troubleshooting intermittent communication between two devices on the same Ethernet switch. The devices are on the same IP subnet. The technician runs 'arp -a' on one device and sees the other device's IP address mapped to an incorrect MAC address. What is the most likely cause?

   • AThe switch has a MAC address table that is full.
   • BThe device's ARP cache is stale and has not refreshed the mapping.
   • CThe devices are on different VLANs.
   • DThe switch is a hub.
   Reveal Solution Discussion Select an answer first