220-1102 Question 193
Single answer.appA support technician is helping a user access a company web application hosted at helpdesk.app. The user reports that the site works on a smartphone over cellular data, but on the office Windows PC, entering http://helpdesk.app in the browser fails immediately and the browser indicates the site cannot be reached. Other websites load normally. The technician wants to identify the MOST likely cause before escalating the issue. What is the best explanation?
- A
The .app domain requires HTTPS, so attempts to use plain HTTP will fail
- B
The Windows PC must have a locally installed .app package to open .app websites
- C
The browser does not support newer top-level domains such as .app
- D
The office network is blocking all domains that are not .com or .net
Show answer and explanation
Correct answer: A
Explanation
The best answer is that .app domains are HTTPS-only in practice because the .app TLD is on the HSTS preload list. HSTS (HTTP Strict Transport Security) tells browsers to use secure HTTPS connections and not allow insecure HTTP access. For a technician, this is a practical troubleshooting point: if a user enters an http:// URL for a .app site, the browser will require HTTPS. The technician should verify the site is reachable at https://helpdesk.app and confirm the certificate is valid. This aligns with web security best practices and browser behavior documented by HSTS preload guidance and .app domain security requirements.
- A. Correct.
Correct. The .app top-level domain is included on the HSTS preload list, which means browsers are expected to connect using HTTPS only. If a user explicitly types http://helpdesk.app, the browser upgrades or requires a secure connection. A site under .app that is not properly available over HTTPS will fail to load. In practice, technicians should verify that the user is using https:// and that the site has a valid TLS certificate.
- B. Incorrect.
Incorrect. A .app domain is a web domain, not a requirement for an installed local application package. This option reflects a common misunderstanding between a web domain ending in .app and an application installed on the operating system. Accessing a .app website only requires a supported web browser and network connectivity.
- C. Incorrect.
Incorrect. Modern browsers support current ICANN-recognized top-level domains, including .app. Lack of support for the TLD itself is not a realistic cause on a current A+ Core 2-style troubleshooting scenario, especially when the issue is limited to using HTTP rather than HTTPS.
- D. Incorrect.
Incorrect. While content filtering or DNS policy could block specific domains, there is no standard office network policy that inherently blocks all non-.com or non-.net domains, and the scenario does not suggest a broad DNS restriction. Also, the clue that the user is specifically trying http://helpdesk.app points more directly to HTTPS enforcement on the .app domain.