220-1101 Question 470
Single answerConnectivity issuesA technician is troubleshooting a Windows laptop that can connect to the company Wi-Fi but cannot reach any internal servers or Internet sites. Other users on the same wireless network have no issues. The technician runs ipconfig and sees the laptop has an IPv4 address of 169.254.88.23 with a subnet mask of 255.255.0.0 and no default gateway. Which of the following is the MOST likely cause of the problem?
- A
The laptop failed to obtain an IP address from the DHCP server
- B
The wireless access point is configured with the wrong SSID
- C
The laptop has an incorrect DNS server configured
- D
The company router is blocking HTTPS traffic
Show answer and explanation
Correct answer: A
Explanation
This question tests recognition of a classic connectivity issue: APIPA addressing caused by DHCP failure. In Windows, when a client cannot contact a DHCP server and cannot obtain a valid lease, it may assign itself an address in the 169.254.0.0/16 range. That allows only limited local-link communication and does not provide a usable default gateway for reaching other networks. From a CompTIA A+ Core 1 perspective, the best troubleshooting path is to identify the invalid IP configuration first, then renew the lease, verify the wireless adapter status, check DHCP availability, and confirm the client is connecting to the correct network profile. Microsoft documentation on APIPA and TCP/IP troubleshooting supports that a 169.254.x.x address usually indicates a DHCP communication problem rather than DNS failure, SSID naming issues, or protocol-specific filtering.
- A. Correct.
Correct. An address in the 169.254.0.0/16 range is an APIPA (Automatic Private IP Addressing) address assigned by Windows when the client cannot obtain a lease from a DHCP server. Because there is also no default gateway listed, the laptop will be unable to communicate beyond the local link. In a scenario where other users on the same Wi-Fi are working, the issue is most likely specific to this client's ability to receive a DHCP lease rather than a network-wide outage.
- B. Incorrect.
Incorrect. If the access point were using the wrong SSID, the laptop typically would not be connected to the expected wireless network at all, or users broadly would be connecting to the wrong network. The scenario states the laptop is connected to the company Wi-Fi and other users on that same network are functioning normally. The IP configuration shown points to a DHCP failure, not an SSID mismatch.
- C. Incorrect.
Incorrect. A DNS misconfiguration can prevent name resolution, but it would not cause the system to self-assign a 169.254.x.x address or remove the default gateway. With bad DNS, the user might still be able to reach resources by IP address. Here, the laptop lacks valid Layer 3 configuration, so the issue occurs before DNS becomes the primary concern.
- D. Incorrect.
Incorrect. Blocking HTTPS traffic would affect secure web access, but it would not explain the APIPA address or the missing default gateway. In addition, the user cannot reach internal servers or any Internet sites, which is broader than a protocol-specific filtering problem. The symptom set is consistent with failure to obtain network addressing information.