Introducing TCP/IP Networks ICSSCADA Practice Questions (Page 7)

Questions 31–35

1. 31expert · hard

   A SCADA network uses a DHCP server to assign IP addresses to field devices. A new device is added and receives an IP address, but it cannot communicate with other devices on the same subnet. The device's IP address is 192.168.1.50/24, and the subnet is 192.168.1.0/24. Which configuration is most likely the cause?

   • AThe device's subnet mask is incorrect.
   • BThe device's DNS server is not configured.
   • CThe device's default gateway is not set.
   • DThe device's IP address is a duplicate of another device.
   Reveal Solution Discussion Select an answer first
2. 32expert · hard

   A security analyst is reviewing firewall logs and sees a connection from an external IP to port 502 on a SCADA device. The device is behind a NAT. The firewall has a rule allowing inbound TCP 502 to the device's public IP. What is the most likely purpose of this rule?

   • ATo allow the SCADA device to initiate outbound connections to the internet.
   • BTo allow DNS resolution for the SCADA device.
   • CTo allow secure shell management of the SCADA device.
   • DTo allow remote engineering access to the SCADA device using Modbus TCP.
   Reveal Solution Discussion Select an answer first
4. 33foundation · easy

   In the TCP/IP model, which layer is responsible for ensuring reliable, ordered delivery of data between applications?

   • AApplication layer
   • BInternet layer
   • CTransport layer
   • DNetwork access layer
   Reveal Solution Discussion Select an answer first
5. 34foundation · easy

   Which application-layer protocol is designed for transferring files between a client and a server over a network?

   • ASSH
   • BHTTP
   • CDNS
   • DFTP
   Reveal Solution Discussion Select an answer first
6. 35application · medium

   A workstation in the IT network cannot reach a new HMI server in the OT network. The workstation's default gateway is reachable, but the HMI server's IP address does not respond to ping. Which pair of protocols would you use to isolate whether the problem is at layer 2 or layer 3?

   • AUse NAT to translate the workstation's address, then use a routing protocol to advertise the HMI server's subnet.
   • BUse DNS to resolve the HMI server's hostname, then use DHCP to confirm it has a valid IP address.
   • CUse TCP to test the HMI server's port 80, then use UDP to test its port 53.
   • DUse ARP to verify the gateway's MAC address is resolved, then use ICMP to test end-to-end reachability to the HMI server.
   Reveal Solution Discussion Select an answer first