How to Fix the Private DNS Server Cannot Be Accessed Error

So, you got the “private DNS server cannot be accessed” message? Don’t fret. This issue is common on Android phones, and usually comes down to one of a handful of causes, most of which have a quick fix.

The most common culprit is a typo in your DNS hostname, so that’s the first thing to check. If that’s not it, this guide walks you through the other likely causes and how to resolve each one. 

How to Fix the “Private DNS Server Cannot Be Accessed” Issue

• Restart your device: A simple restart can clear any temporary connection issues. It’s always worth trying before making changes to your settings.
• Verify the DNS hostname: It could be a simple typo. Double-check that you have spelled the hostname correctly and that it matches the DNS provider you’re trying to use. 
• Visit your DNS provider’s status page: If there’s a maintenance process or an unexpected outage going on, the most popular DNS providers usually post live updates on their status page. If that’s the case, you simply need to wait.
• Check whether the issue is device- or network-specific: Try another device or network. If the error persists, the problem likely lies with your DNS settings rather than your internet connection.
• Test your network: If your network is blocking your private DNS, you can run a few tests to verify. First, connect to another network to see if the private DNS feature works properly. If your network is blocking the specific DNS provider you’re using, you can also try switching to another DNS service.
• Update your operating system: Sometimes, your device’s latest operating system or app updates include bug fixes that could solve your DNS issue. 

Why Do I See a “Private DNS Server Cannot Be Accessed” Message?

While private DNS has become a useful tool to add an extra security layer to your online activity, it isn’t always enabled by default. That means you may run into errors when trying to use it or during setup. 

The Most Common Reasons for Private DNS Errors

1. A typo in your private DNS hostname: When you set up private DNS, you can either let your device use the network’s default DNS settings automatically or manually add a private DNS provider’s hostname. If you enter the wrong hostname, you’ll get this error.
2. The DNS provider is down or overloaded: Sometimes, the DNS server you’re trying to use is temporarily unavailable because of maintenance, outages, or heavy traffic. In that case, your device may not be able to validate the connection.
3. Your network connection isn’t stable enough: The DNS over TLS protocol used by Android devices requires a stable connection to work properly. A weak or unstable internet connection can trigger a “private DNS server not responding” or similar error message. 
4. The network is blocking the connection: If you’re connecting from your school, library, or workspace, the network might be blocking private DNS. 
5. Your ISP isn’t allowing the connection: Port 853 may be blocked on your network. This port is required for the DNS over TLS protocol used by Android’s private DNS feature. Although this usually happens more in countries with restrictive internet policies, it can occur anywhere.
6. Your VPN is overriding DNS settings: If you’re using a VPN, private DNS probably won’t work. VPNs may route DNS requests through their own servers instead of using Android’s private DNS feature, and use different security protocols to encrypt your browsing activity. 

What Is a Private DNS Server?

A Domain Name System (DNS) translates the website names you use and remember, like privateinternetaccess.com, into numerical IP addresses that computers use, like 203.0.113.25. DNS servers can be public or private. The majority of the internet uses public DNS servers, but some organizations and people who want more privacy online often rely on private DNS.

Since the introduction of Android 9 back in 2018¹, many Android devices include a built-in private DNS feature that encrypts your DNS queries and makes it more difficult for people on the same network to see the websites and services you’re using. 

How to Avoid the “Private DNS Server Cannot Be Accessed” Error

Once you’ve fixed the “private DNS server cannot be accessed” error, there are a few simple things you can do to avoid seeing it again in the future:

• Use a trustworthy DNS service provider: If you’re configuring your device to use a private DNS service, make sure this provider is reliable. 
• Keep your device and apps updated: Having your operating system and your browser apps up to date will help avoid bugs and network connection issues. 
• Be mindful of the networks you connect to: You might forget that you’re using a restrictive network or an unreliable connection that might be disrupting your private DNS service.

FAQ

References:

1. DNS over TLS support in Android P Developer Preview – Android Developers Blog