How can you troubleshoot DNS resolution failures on a MacBook Pro running the latest version of macOS?

1 Check Network

Firstly, verify your network connection. A simple yet often overlooked step is ensuring your MacBook Pro is connected to the internet. Open a browser and try visiting a few different websites. If none load, the issue might be with your network rather than DNS. Check your Wi-Fi or Ethernet connection and ensure airplane mode is not enabled. If other devices on the same network are also experiencing issues, rebooting your router could resolve the problem.

2 Flush DNS Cache

Next, flush your DNS cache. This is akin to clearing your browser's history and can resolve stale or corrupt entries that might cause resolution failures. To flush the DNS cache on macOS, open the Terminal application and enter sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder . You'll need to enter your administrator password. This resets the DNS cache, potentially fixing resolution issues.

3 Update macOS

Keeping macOS updated is crucial for system stability and performance. Apple often releases patches for known issues, which could include DNS problems. To check for updates, go to the Apple menu, select 'System Preferences,' then 'Software Update.' If an update is available, follow the on-screen instructions to install it. This might resolve any DNS resolution issues caused by outdated system files.

4 Change DNS Server

Consider changing your DNS server. Sometimes, the default server provided by your Internet Service Provider (ISP) could be down or performing poorly. You can switch to public DNS services like Google DNS or OpenDNS for better reliability. To change the DNS server on a MacBook Pro, go to 'System Preferences,' click 'Network,' select your active connection, click 'Advanced,' and navigate to the 'DNS' tab where you can add new DNS servers.

5 Disable VPN/Proxy

If you're using a VPN (Virtual Private Network) or proxy service, it could interfere with DNS resolution. Try disabling these services temporarily to see if that resolves the issue. Go to 'System Preferences,' select 'Network,' and find your VPN or proxy service in the list. Click on it and then choose 'Disconnect' or uncheck any options that enable it at startup. This can help identify if these services are the root cause of DNS problems.

6 Contact ISP

Lastly, if you've tried all the above steps without success, it might be time to contact your ISP. There might be a larger issue at play with their DNS servers or a network outage in your area. Your ISP's support can provide further insights and help resolve issues that are out of your control. They can also confirm if there's a widespread problem affecting other users, which might require patience until they resolve it.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?