220-1201 Practice Question: A customer reports that their desktop computer,…

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  The switch is a hub, not a switch.

  Why it's wrong here

  A hub operates at Layer 1 of the OSI model, simply repeating all incoming electrical signals to every other port. While this creates a single collision domain and significantly reduces network performance due to frequent collisions, all devices connected to a hub remain within the same broadcast domain. Consequently, devices would still be able to send and receive broadcast frames, such as ARP requests, allowing them to discover and communicate with each other at Layer 2, even if internet access is slow.

• ✓

  The computer's network profile is set to 'Public', disabling Network Discovery.

  Why this is correct

  In Windows, setting a network profile to 'Public' applies a more restrictive firewall configuration, suitable for untrusted networks like public Wi-Fi hotspots. This profile aggressively disables Network Discovery and file/printer sharing by default, preventing the computer from being visible to other devices on the local network and blocking unsolicited incoming connections. Despite this, outbound connections, such as accessing the internet, are typically still permitted, aligning perfectly with the described symptom.

• ✗

  The router is blocking multicast traffic.

  Why it's wrong here

  Routers primarily operate at Layer 3 and are designed to segment networks, preventing broadcast and multicast traffic from traversing between different subnets by default. However, local network discovery protocols, like ARP or NetBIOS over TCP/IP, rely on broadcasts or link-local multicasts that occur *within* the same Layer 2 segment (e.g., a single switch or VLAN). Therefore, if the desktop computer and other local devices are on the same subnet and switch, the router's multicast blocking configuration would not impact their ability to discover each other locally.

• ✗

  The Ethernet cable is a crossover cable.

  Why it's wrong here

  Historically, a crossover Ethernet cable was required to connect two similar devices directly (e.g., PC to PC, switch to switch) by swapping the transmit and receive wire pairs. However, virtually all modern network interface cards (NICs) and network switches are equipped with Auto-MDIX (Automatic Medium-Dependent Interface Crossover) technology. This feature automatically detects the cable type and adjusts the port's wiring configuration as needed, rendering crossover cables largely obsolete. If Auto-MDIX were not present or failed, a crossover cable would typically result in a complete link failure, preventing any network communication whatsoever, rather than just a loss of local visibility.