Core 1: Hardware & Network Troubleshooting

At boot, a workstation warns that its hard drive has reported a S.M.A.R.T. failure, although Windows still loads normally. What should the technician do first?

• ARun a full defragmentation pass to repair the failing sectors
• BBack up the user's data now and plan to replace the drive✓
• CClear the warning in UEFI and check it again next month
• DReinstall Windows to rewrite the damaged system files

Answer: A S.M.A.R.T. failure is the drive's own prediction that it is about to fail; working today does not mean it will keep working, so secure the data first and replace the drive. Defragmenting or reinstalling puts heavy writes on a failing disk, and silencing the warning ignores the risk.

A switch log shows the port serving one office PC going up and down every few seconds. What is the most likely cause of this port flapping?

• AA DHCP scope that has run out of leases for the VLAN
• BA damaged patch cable or a failing NIC on that link✓
• CAn incorrect DNS server address configured on the PC
• DA full MAC address table in the switch's memory

Answer: Port flapping means the physical link keeps dropping and re-establishing, which points to layer 1 faults: a damaged or badly terminated cable, a loose connector or a failing network card (a speed or duplex mismatch can also cause it). DHCP and DNS problems break addressing or name resolution but leave the link up, and a full MAC table causes flooding rather than link loss.