220-1102 Question 104
Single answeripconfigA Windows 11 laptop in a small office suddenly cannot reach any internal servers or the internet after being moved to a different desk. The user confirms the Ethernet cable is plugged in and the link light is on. You open Command Prompt and need to quickly verify whether the computer received a valid IPv4 configuration from DHCP, including its IP address, subnet mask, default gateway, and DNS servers. Which command should you run first?
- A
ipconfig /all
- B
ipconfig /release
- C
ipconfig /flushdns
- D
ipconfig /displaydns
Show answer and explanation
Correct answer: A
Explanation
When troubleshooting a suspected DHCP or connectivity issue on Windows, a best-practice first step is to inspect the current network configuration before making changes. The "ipconfig /all" command is specifically used to display detailed adapter information, including IPv4 address, subnet mask, default gateway, DNS servers, and DHCP details. If the system shows an Automatic Private IP Addressing (APIPA) address in the 169.254.0.0/16 range, that strongly suggests it did not obtain a lease from a DHCP server. After confirming the current state, a technician might proceed with commands such as "ipconfig /release" and "ipconfig /renew" if appropriate. This aligns with standard Windows command-line troubleshooting practices documented by Microsoft for the ipconfig utility.
- A. Correct.
Correct. "ipconfig /all" displays detailed TCP/IP configuration for each adapter, including the IPv4 address, subnet mask, default gateway, DHCP status, DHCP server, and DNS servers. In this scenario, that is the best first step because it lets you verify whether the laptop received a valid lease or has an APIPA address such as 169.254.x.x.
- B. Incorrect.
Incorrect. "ipconfig /release" drops the current DHCP lease on DHCP-enabled adapters. That may be useful later if you determine the lease is invalid and want to request a new one, typically followed by "/renew". However, it is not the best first command when you still need to inspect the current configuration.
- C. Incorrect.
Incorrect. "ipconfig /flushdns" clears the local DNS resolver cache. This can help when a system is resolving hostnames to stale or incorrect addresses, but it does not show the current IP settings and would not help confirm whether the device has a valid DHCP-assigned IPv4 configuration.
- D. Incorrect.
Incorrect. "ipconfig /displaydns" shows the contents of the local DNS cache. That can be useful for name resolution troubleshooting, but it does not display the adapter's full network configuration such as subnet mask, gateway, or DHCP information.