220-1102 Question 210
Single answerNetworksA technician is troubleshooting a Windows 11 laptop that connects successfully to the office Wi-Fi but cannot open internal file shares or browse the internet. Other users on the same wireless network are working normally. The technician runs ipconfig and sees the laptop has an IPv4 address of 169.254.22.81 with a subnet mask of 255.255.0.0 and no default gateway. Which of the following is the MOST likely cause?
- A
The laptop failed to obtain an address from the DHCP server
- B
The wireless adapter is using an incorrect DNS server
- C
The office router is blocking the laptop's MAC address
- D
The laptop is connected to the wrong SSID with weak signal strength
Show answer and explanation
Correct answer: A
Explanation
This scenario tests practical recognition of APIPA addressing in Windows. When a client cannot obtain an IPv4 lease from DHCP, Windows commonly assigns an address in the 169.254.0.0/16 range as defined for link-local addressing. Because APIPA is only locally significant, the device generally cannot communicate beyond its local segment and will not have a usable default gateway for routed traffic. In real troubleshooting, the technician should next verify DHCP availability, check whether the wireless adapter is set to obtain an IP address automatically, renew the lease with ipconfig /release and ipconfig /renew, and confirm that the DHCP server or wireless infrastructure is functioning correctly. This aligns with standard Microsoft Windows TCP/IP troubleshooting practices and common CompTIA A+ network troubleshooting objectives.
- A. Correct.
Correct. An address in the 169.254.0.0/16 range is an Automatic Private IP Addressing (APIPA) address, which Windows assigns when it cannot contact a DHCP server and no static IP is configured. The lack of a default gateway further supports this, because a system that self-assigns APIPA typically will not have valid gateway or DNS settings. In a business network, this would prevent access to both internal resources on other subnets and the internet.
- B. Incorrect.
Incorrect. Bad DNS settings can prevent name resolution, but they do not cause a host to self-assign a 169.254.x.x address. A system with only a DNS issue would usually still have a valid IP address, subnet mask, and default gateway from DHCP or a static configuration, and it could often still reach resources by IP address.
- C. Incorrect.
Incorrect. A MAC filtering issue could prevent successful network access, but the key evidence here is the APIPA address and missing default gateway. Those symptoms point specifically to a failure to receive DHCP configuration rather than selective filtering after a proper lease was assigned.
- D. Incorrect.
Incorrect. Connecting to the wrong SSID or having a poor signal can cause intermittent connectivity, but the IP configuration shown is the stronger clue. If the laptop were simply on the wrong SSID, it would more likely receive a valid address from that network's DHCP scope, not an APIPA address unless DHCP communication failed entirely.