TCP/IP Protocol Architecture ICSSCADA Practice Questions (Page 3)

Questions 11–15

1. 11application · medium

   A SCADA network uses a proprietary protocol that sends small, frequent status messages between controllers. The messages are time-critical and the application can tolerate occasional loss. The network also carries file transfers of historical logs from the historian to a backup server. Which transport protocol should be used for each application?

   • AUDP for status messages and TCP for file transfers
   • BUDP for both status messages and file transfers
   • CTCP for status messages and UDP for file transfers
   • DTCP for both status messages and file transfers
   Reveal Solution Discussion Select an answer first
2. 12expert · medium

   An engineer is planning the IP addressing for a new wind farm SCADA network. The network will have 10 turbines, each with a PLC and a local HMI. The engineer wants to use a single subnet for all devices. Which subnet mask provides the smallest subnet that can accommodate 20 devices with room for 2 additional devices?

   • A255.255.255.248
   • B255.255.255.240
   • C255.255.255.224
   • D255.255.255.192
   Reveal Solution Discussion Select an answer first
4. 13foundation · easy

   What is the correct order of encapsulation when a web browser sends an HTTP request over a TCP/IP network?

   • AData → IP packet → TCP segment → Ethernet frame
   • BEthernet frame → IP packet → TCP segment → Data
   • CData → TCP segment → IP packet → Ethernet frame
   • DTCP segment → Data → IP packet → Ethernet frame
   Reveal Solution Discussion Select an answer first
5. 14application · medium

   A plant network uses a mix of IPv4 and IPv6 devices. The SCADA server needs to communicate with a new field device that only supports IPv6. The server's network stack is configured with both IPv4 and IPv6 addresses. The engineer notices that the server sends an ICMPv6 Neighbor Solicitation to resolve the field device's link-layer address. Which protocol is being used and why?

   • AARP is used for address resolution in IPv6, just as in IPv4.
   • BDNS is used to resolve the link-layer address.
   • CICMPv6 is used for address resolution in IPv6, replacing ARP.
   • DThe server uses TCP to establish a connection before resolving the address.
   Reveal Solution Discussion Select an answer first
6. 15application · medium

   A firewall rule on an ICS DMZ allows inbound traffic to the engineering workstation's IP address on TCP port 3389. A remote engineer reports that the Remote Desktop connection fails. What is the most likely cause?

   • AThe workstation's IP address is not in the same subnet as the firewall.
   • BThe workstation's Remote Desktop service is listening on a different port.
   • CThe firewall rule is blocking outbound traffic from the workstation.
   • DThe workstation is using UDP instead of TCP for Remote Desktop.
   Reveal Solution Discussion Select an answer first