CompTIA A+ Core 1 (220-1201)Hardware and Network TroubleshootingMedium
A technician is troubleshooting a client's desktop that intermittently loses network connectivity. The client reports that the network icon in the system tray shows a 'limited connectivity' or 'no internet access' warning, but sometimes resolves itself after a few minutes. Other devices on the same network operate without issue. Which of the following is the MOST likely cause?
- APhysical damage to the network cable
- BA DHCP server issue on the network
- CAn incorrect subnet mask on the client's workstation
- DA failing network interface card (NIC)
Show answer & explanationAnswer & explanation
Correct answer: D. A failing network interface card (NIC)
Intermittent network connectivity issues, especially when other devices on the same network are fine, often point to a problem with the local network interface card (NIC). A failing NIC can cause sporadic disconnections, limited connectivity, or difficulty obtaining/maintaining an IP address.
Why the other options are wrong
- A. Physical damage to the network cable would likely cause a complete loss of connection or very consistent drops, not intermittent resolution.
- B. A DHCP server issue would affect all or many devices on the network, preventing them from obtaining IP addresses, not just one workstation intermittently.
- C. An incorrect subnet mask would cause consistent network issues, preventing communication outside the local subnet entirely, not intermittent problems that resolve themselves.
Intermittent Network Connectivity
Intermittent network connectivity issues on a single workstation, while other devices on the same network function correctly, strongly suggest a problem with the workstation's Network Interface Card (NIC) or its driver.
- Problem isolated to one device
- Sporadic disconnections/reconnections
- NIC is responsible for physical network communication
- Driver issues can also cause this
Memory trick: NIC is Nasty, Causing Connectivity Chaos.