A small office has 12 computers connected to a single unmanaged switch, which is connected to a router providing internet access. Users report that at random times, all computers lose internet connectivity for a few seconds, then it returns. The technician observes that when the problem occurs, the lights on the switch do not change, but a Ping to the router fails. The technician has replaced the router and the switch, but the issue persists. Which of the following is the MOST likely cause?

A: A bad Ethernet cable between the switch and router

A bad cable would cause physical layer issues, often reflected by changing link lights. The technician observed no change on switch lights, making this unlikely.

C: A failing network card in one of the computers

A faulty NIC on a single device would only affect that device, not all computers simultaneously.

D: A misconfigured firewall rule on the router

A misconfigured firewall rule typically blocks traffic consistently, not intermittently. Also, the router was replaced, so the original configuration is gone.

What does this 220-1101 question test?

Read the scenario before looking for a memorised answer.

What is the correct answer to this question?

The correct answer is: B: A user's device acting as a rogue DHCP server — A rogue DHCP server (e.g., a personal router or a misconfigured device) can assign invalid IP addresses or create IP conflicts, causing temporary internet loss for all devices. Since the switch and router were replaced, the issue persists, pointing to a device on the network that is interfering. A faulty cable or NIC would only affect one device, and a firewall rule would not be intermittent in this manner.

What should I do if I get this 220-1101 question wrong?

Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.