How to Analyze and Fix Chrome DNS Failures with net-internals

Google Chrome is one of the most widely used web browsers globally, appreciated for its speed, security, and simplicity. However, like any software, Chrome can occasionally encounter connectivity issues, and one common problem users face is DNS failures. These failures can prevent you from loading websites, showing errors such as "DNS_PROBE_FINISHED_NXDOMAIN" or "DNS_PROBE_FINISHED_BAD_CONFIG".

Fortunately, Chrome includes built-in diagnostic tools that allow users and IT professionals to analyze and troubleshoot DNS-related issues effectively. The net-internals tool (now integrated into Chrome's developer tools) provides detailed insight into Chrome's networking internals, including DNS caching, DNS resolution processes, and potential failures.

This knowledgebase article will walk you through:

• Understanding DNS failures in Chrome
  
  

• Accessing and using Chrome's net-internals tool
  
  

• Analyzing DNS failures using net-internals
  
  

• Common fixes for Chrome DNS failures
  
  

• Tips to prevent DNS issues in the future
  
  

What is a DNS Failure in Chrome?

Before diving into the diagnostic process, it's important to understand what a DNS failure means.

DNS (Domain Name System) is like the phonebook of the internet. It translates domain names like www.example.com into IP addresses that computers use to communicate.

A DNS failure in Chrome occurs when the browser cannot resolve a website's domain name to its IP address. This can happen for several reasons:

• Problems with your local DNS cache
  
  

• Issues with your configured DNS server
  
  

• Network connectivity problems
  
  

• Incorrect DNS settings or firewall restrictions
  
  

• Temporary glitches in Chrome's DNS resolver
  
  

When DNS fails, Chrome cannot connect to the website, resulting in error messages such as:

• ERR_NAME_NOT_RESOLVED
  
  

• DNS_PROBE_FINISHED_NXDOMAIN
  
  

• DNS_PROBE_FINISHED_BAD_CONFIG
  
  

Accessing Chrome's net-internals Tool

Chrome's net-internals is a powerful diagnostic interface that provides granular details about network events, including DNS resolution.

Note: Starting with Chrome version 79, the legacy chrome://net-internals URL has been deprecated. The DNS section has been moved under chrome://net-export and Chrome Developer Tools. However, the traditional DNS cache and diagnostics can still be accessed via the following:

Step 1: Open Chrome and access the net-internals DNS page

• Type chrome://net-internals/#dns in the address bar and press Enter.
  
  

• This page shows Chrome's DNS cache entries, host resolver statistics, and allows you to clear DNS cache.
  
  

Step 2: Use Chrome Developer Tools for advanced diagnostics

• Press Ctrl+Shift+I (Windows/Linux) or Cmd+Option+I (Mac) to open Developer Tools.
  
  

• Go to the Network tab.
  
  

• Reload the page experiencing DNS issues to view network requests and status codes.
  
  

• You can also capture a detailed network log by clicking the record button.
  
  

Step 3: Export network logs for in-depth analysis

• For advanced users or network admins, visit chrome://net-export/
  
  

• Click "Start Logging to Disk" to capture a detailed log of network events.
  
  

• Reproduce the DNS failure, then stop logging and analyze the JSON file with tools like Netlog Viewer.
  
  

Analyzing DNS Failures Using net-internals

Once you're on the chrome://net-internals/#dns page, here's what you can do:

1. View DNS cache entries

Chrome caches DNS resolutions for a period to speed up subsequent requests. On the DNS page, you'll see a list of domain names and their resolved IP addresses currently cached.

• Check if the domain you're trying to access appears here.
  
  

• If it appears with an error status or is missing, Chrome might be failing to resolve it.
  
  

2. Clear the DNS cache

Sometimes the cached DNS information is outdated or corrupted. Clearing the cache forces Chrome to re-query the DNS server.

• Click the "Clear host cache" button on the page.
  
  

• After clearing, try reloading the website to see if the DNS failure is resolved.
  
  

3. Check Host Resolver Statistics

On the same page, you can scroll down to see statistics about DNS queries, such as success rates and failures. High failure counts indicate persistent DNS resolution issues.

4. Analyze network requests in Developer Tools

In the Network tab, look for requests that failed with DNS-related errors. Check the status codes and timing to confirm if DNS lookup was the issue.

Common Fixes for Chrome DNS Failures

After diagnosing the issue using net-internals, you can try the following fixes to resolve DNS problems in Chrome:

1. Clear Chrome's DNS Cache

As explained, visit chrome://net-internals/#dns and click Clear host cache.

2. Flush your system's DNS cache

Sometimes the issue lies with your operating system's DNS cache, not just Chrome. Here's how to flush it:

Windows:
Open Command Prompt and run:

bash
CopyEdit
ipconfig /flushdns  

macOS:
Open Terminal and run:

nginx
CopyEdit
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder  

Linux:
Depending on the distribution, try:

arduino
CopyEdit
sudo systemd-resolve --flush-caches  

3. Change your DNS server

Your current DNS server might be unreliable or slow. Switching to public DNS servers like Google DNS (8.8.8.8 and 8.8.4.4) or Cloudflare DNS (1.1.1.1) often improves DNS resolution.

• On Windows or macOS, change the DNS settings in your network adapter or system preferences.
  
  

• On routers, update DNS settings so all connected devices benefit.
  
  

4. Disable DNS Prediction Service (Pre-fetching)

Chrome uses DNS prefetching to speed up browsing, but sometimes this can cause issues.

• Go to chrome://settings/privacy
  
  

• Disable "Preload pages for faster browsing and searching" under the Privacy and security section.
  
  

5. Reset Chrome Flags related to DNS

Sometimes experimental flags interfere with DNS resolution.

• Visit chrome://flags
  
  

• Search for any DNS-related flags like Async DNS, Built-in DNS client and reset them to default.
  
  

6. Disable VPN or Proxy Temporarily

VPNs or proxies can interfere with DNS resolution. Temporarily disable them and check if DNS failures persist.

7. Restart your Router and Computer

Network hardware issues can cause DNS failures. Restarting your router and computer often fixes transient DNS issues.

Tips to Prevent Future DNS Failures in Chrome

• Regularly clear your DNS cache in Chrome and your system.
  
  

• Use a reliable DNS provider with good uptime.
  
  

• Keep Chrome updated to the latest version to benefit from bug fixes and improvements.
  
  

• Avoid running conflicting network software that might interfere with DNS (e.g., multiple VPN clients).
  
  

• Consider using Chrome's built-in Net Export logs periodically to monitor network health in complex environments.
  
  

Summary

DNS failures in Google Chrome can be frustrating but are often easy to diagnose and fix using Chrome's net-internals tool and a few straightforward system adjustments. By accessing Chrome's DNS diagnostics, clearing caches, changing DNS servers, and ensuring a stable network environment, you can quickly restore your browsing experience.

If issues persist even after trying these fixes, the problem may be on the DNS server side or with your internet service provider, in which case contacting your ISP or network administrator for further support is recommended.

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