Configure Chrome OS for Secure DNSaaS

📋 Overview

Chrome OS includes built-in support for DNS-over-HTTPS (DoH) with custom providers. This guide will help you configure Chrome OS to use our secure DNSaaS service with token-based authentication.

Service	Endpoint	Authentication
Primary DNS	`https://dns1.oss.co.za/xxxxx{?dns}`	Token in URL path
Protocol	DNS-over-HTTPS (DoH) • Port 443 • TLS 1.3
Chrome OS Version	Version 80+ (all recent versions)

💡 Chrome OS vs Other Platforms Chrome OS uses the same Chromium engine as Google Chrome, so the endpoint format is the same: {?dns} with curly braces.

✅ Prerequisites

Chrome OS 80 or newer
Your token: token_testclient123 (replace with your actual token)
Administrative access (managed device may restrict DNS settings)
Internet connectivity

💡 Token Format Your token is provided by the DNSaaS administrator. It looks like: token_xxxxxxxxxx

⚠️ Managed Devices If your Chromebook is managed by a school or organization, DNS settings may be locked. Contact your administrator for assistance.

💻 Configure Chrome OS Step-by-Step

1 Open Chrome OS Settings

Click the time in the bottom-right corner of the screen.

Click the gear icon to open Settings.

Alternatively, type chrome://settings/ in the Chrome browser address bar.

2 Navigate to Network Settings

In the Settings sidebar, click Network.

Select your active network connection (Wi-Fi or Ethernet).

3 Go to DNS Settings

Click on the name of your connected network.

Scroll down to the Network settings section.

Click on DNS or Name servers.

💡 Alternative Path You can also go to Settings → Security and Privacy → Security → Use secure DNS if available on your version.

4 Enable Custom DNS

Change from Automatic to Custom name servers.

Enter your primary and secondary DNS server IPs:

102.220.218.218

102.220.218.219

5 Configure DNS-over-HTTPS (DoH)

If your Chrome OS version supports DoH, look for "DNS-over-HTTPS" or "Secure DNS" options.

Enter the following URL (replace token_testclient123 with your token):

https://dns1.oss.co.za/testclient123{?dns}

⚠️ Important

Replace token_testclient123 with your actual token
Chrome OS requires the {?dns} template variable
Use curly braces { }, not parentheses ( )

6 Save and Validate

Click Apply or Save to apply the changes.

Open Chrome browser and test:

chrome://net-internals/#dns

Clear the DNS cache and verify queries are being resolved through your DNSaaS service.

📱 Alternative: Android Settings (for Chromebooks with Google Play)

If your Chromebook supports Android apps, you can also configure DNS using the Android Private DNS feature.

Step 1: Open Android Settings

Click the time in the bottom-right corner → gear icon → Apps → Google Play Store.

Or use the Android Settings app (if available).

Step 2: Navigate to Private DNS

Go to Network & internet → Private DNS.

Step 3: Enter DoT Hostname

Select Private DNS provider hostname and enter:

dns1.oss.co.za

⚠️ Important Android Private DNS uses DoT (DNS-over-TLS), not DoH. Your token may not work with this method unless your DoT server supports token authentication via SNI.

Step 4: Save and Verify

Tap Save and verify the connection status.

🧪 Test Your Configuration

Use these test sites to verify your Chrome OS configuration is working correctly.

Command Line Tests (Crosh)

Press Ctrl + Alt + T to open Crosh (Chrome OS shell).

Command	Expected Result
`dig example.com`	✅ Should return A records
`dig zycdjz.com`	❌ Should return NXDOMAIN (blocked)

Browser Tests

Test Domain	Expected Result
`https://example.com`	✅ Should load normally
`http://zycdjz.com`	❌ Should show "This site can't be reached"
`http://adult.filterdns.net`	❌ Should show "This site can't be reached"

DNS Leak Test

Test Domain	Expected Result
`https://dnsleaktest.com`	Should show `dns1.oss.co.za` or `102.220.218.218`

🔧 Troubleshooting

❌ DNS settings are locked or greyed out

Your Chromebook may be managed by a school or organization
Contact your administrator to request DNS changes
Consider using a third-party app or Android Private DNS

❌ "Please verify that this is a valid provider"

Make sure you're using the correct format: https://dns1.oss.co.za/xxxxx{?dns}
Use curly braces { }, not parentheses ( )
Check that your token is valid and active

❌ DoH option not available in Settings

Your Chrome OS version may not support DoH in the GUI
Use the Android Private DNS method as an alternative
Consider using a third-party app like AdGuard or NextDNS

✅ Verify It's Working

Visit chrome://net-internals/#dns and check for DNS-over-HTTPS queries
Visit http://adult.filterdns.net - should show "This site can't be reached"
Visit https://dnsleaktest.com - should show your DNS server
Use Crosh: dig example.com to verify resolution

↩️ How to Roll Back

To revert to your previous DNS settings:

Step 1: Open Network Settings

Click the time → gear icon → Network → select your network.

Step 2: Revert to Automatic DNS

Change Name servers from Custom name servers back to Automatic.

Step 3: Clear DNS Cache

Open Chrome browser and go to:

chrome://net-internals/#dns

Click "Clear host cache".

🎯 Summary

💻 Chrome OS supports DoH natively in Network Settings
✅ Working URL: https://dns1.oss.co.za/xxxxx{?dns}
🔒 All DNS queries are encrypted via DoH (port 443) with TLS 1.3
⚡ Chrome OS uses the {?dns} format (same as Chrome browser)
🔄 Easily toggle on/off as needed

🚀 Quick Reference:

https://dns1.oss.co.za/testclient123{?dns}

💻 Chrome OS Navigation Path:

                Settings → Network → Wi-Fi/Ethernet → [Your Network] → Name servers → Custom
            