Components of TCP/IP Networks ICSSCADA Practice Questions (Page 6)

Questions 26–30

1. 26expert · hard

   A network engineer is troubleshooting intermittent connectivity between two substations connected by a routed link. The engineer discovers that the ARP cache on the router's interface to substation A is frequently being cleared and repopulated. What is the most likely impact of this behavior?

   • AThe router will switch to using IPv6 for all traffic to substation A.
   • BThe router will broadcast all traffic to substation A instead of unicasting.
   • CIncreased latency for the first packet to a destination because the router must perform ARP resolution.
   • DThe router will drop all packets destined for substation A.
   Reveal Solution Discussion Select an answer first
2. 27application · easy

   A technician is setting up a new HMI that must connect to a historian server using the name 'historian.plant.local'. The technician wants to verify that the HMI can resolve this name before configuring the application. Which command should the technician run on the HMI?

   • Anslookup historian.plant.local
   • Bping historian.plant.local
   • Carp -a historian.plant.local
   • Dtracert historian.plant.local
   Reveal Solution Discussion Select an answer first
4. 28application · easy

   A security analyst is reviewing firewall logs and notices outbound connections from an engineering workstation to a remote server on TCP port 22. The workstation is used for PLC programming and file transfers. Which service is the workstation using?

   • ATelnet
   • BHTTP
   • CSecure Shell (SSH)
   • DFTP
   Reveal Solution Discussion Select an answer first
5. 29application · easy

   A technician is configuring a firewall to allow a remote engineer to securely manage a PLC. The engineer will use a command-line interface over an encrypted connection. Which port should the technician allow?

   • ATCP 443
   • BTCP 23
   • CTCP 22
   • DTCP 80
   Reveal Solution Discussion Select an answer first
6. 30application · medium

   A small water treatment plant has a flat network with all PLCs, HMIs, and the SCADA server on the same VLAN. The plant wants to isolate the PLC network from the corporate IT network while still allowing the SCADA server to communicate with both. Which device should be used to segment the traffic and enforce the isolation?

   • AA Layer 2 switch with VLANs configured
   • BA firewall placed between the SCADA server and the PLCs only
   • CA hub connecting all devices
   • DA router with access control lists (ACLs)
   Reveal Solution Discussion Select an answer first