Fixing Mac Wi-Fi Connection Issues Caused by DNS Errors

Step by step

1. 1 min

   Check current DNS configuration

   Open System Settings from the Apple menu and select Wi-Fi. Click the Details button next to your connected network. Select DNS from the left sidebar to view the current server addresses.

   Note: If no servers appear or they are grayed out, your Mac is failing to pull settings from your router.
2. 1 min

   Flush the DNS cache

   Open Terminal from Applications/Utilities. Enter sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder and press Return. Provide your administrator password when prompted.

   Note: The command will not provide a success message; it will simply return to a new prompt line.
3. 2 min

   Add public DNS servers

   Return to System Settings > Wi-Fi > Details > DNS. Click the Plus (+) button and enter 8.8.8.8, then press Enter. Repeat the process to add 1.1.1.1, then click OK to save changes.

   Note: Using public servers often bypasses faulty ISP routing configurations.
4. 1 min

   Delete legacy network preference files

   Open Finder, press Command+Shift+G, and paste /Library/Preferences/SystemConfiguration/. Locate and move com.apple.airport.preferences.plist and com.apple.network.identification.plist to your desktop.

   Note: Restart your Mac after moving these files; macOS will automatically regenerate clean versions.
5. 1 min

   Cycle the network interface

   Turn off Wi-Fi from the Control Center or the menu bar icon. Wait 10 seconds to allow the network interface to power down fully, then toggle Wi-Fi back to the On position.

   Note: Check your browser to see if pages load before proceeding further.