220-1102 Question 134
Single answerWindows Defender FirewallA small office uses a Windows 11 PC to host a line-of-business application for other computers on the local network. After a recent security cleanup, users on other PCs can no longer connect to the application, but the program still works locally on the host computer. The technician confirms the application service is running and the PC has network connectivity. The company wants to restore access for local network users without broadly reducing security. What is the BEST next step?
- A
Turn off Windows Defender Firewall for the Private network profile so other PCs can connect
- B
Create or enable an inbound rule in Windows Defender Firewall that allows the application's required port or executable on the Private profile
- C
Disable Microsoft Defender Antivirus real-time protection because it is blocking the application traffic
- D
Create an outbound rule that allows the application's traffic to leave the host PC
- E
Set the network profile on the host PC to Public so Windows applies stricter controls consistently
Show answer and explanation
Correct answer: B
Explanation
When a Windows PC is hosting an application and other computers cannot connect, the issue is often an inbound filtering problem in Windows Defender Firewall. The most secure and supportable fix is to create or enable a narrowly scoped inbound rule for the specific app or port and apply it only to the appropriate profile, such as Private for a trusted office LAN. This follows Microsoft's recommended best practice of allowing only required traffic rather than disabling the firewall entirely. In Windows, firewall rules can be configured by app, port, protocol, profile, and scope, which lets technicians restore access while minimizing exposure. This scenario reflects a common A+ Core 2 troubleshooting task: identifying whether the problem is caused by inbound versus outbound firewall behavior and choosing the least permissive effective solution.
- A. Incorrect.
This is not the best choice. Disabling Windows Defender Firewall for the Private profile may restore connectivity, but it reduces protection for the entire system rather than allowing only the needed traffic. Best practice is to permit only the specific inbound traffic required by the application.
- B. Correct.
This is correct. If remote clients cannot connect to a service hosted on a Windows PC, the most appropriate fix is to create or re-enable a specific inbound firewall rule for the application's executable or listening port, limited to the correct network profile such as Private. This restores functionality while maintaining the firewall's protections for other traffic.
- C. Incorrect.
This is incorrect. Microsoft Defender Antivirus focuses on malware detection and prevention, not standard network port filtering for hosted services. While antivirus can interfere with some applications in rare cases, the scenario specifically points to remote connectivity to a hosted application, which is most commonly controlled by Windows Defender Firewall inbound rules.
- D. Incorrect.
This is incorrect. For a service hosted on the local PC, remote clients need inbound traffic to be permitted on the host. Outbound rules control traffic leaving the PC, so changing outbound settings would not typically resolve other devices being unable to initiate connections to the application.
- E. Incorrect.
This is incorrect. Changing the network profile to Public would usually make inbound access more restricted, not less. Public profile settings are intended for untrusted networks and commonly block more inbound traffic. It would move the system further away from the stated goal of restoring local network access securely.