How to fix dns server not responding error on Windows, Mac & Linux

If you’ve landed here, you’re probably staring at an error that says “DNS server not responding”, “Your DNS server might be unavailable”, or “No functioning DNS server available” – and your browser isn’t going anywhere.

The good news is that DNS errors, while frustrating, are almost always fixable in a few minutes. This guide walks you through every proven fix in order, from the quick wins to the deeper solutions, covering Windows, Mac, and Linux.

In This Guide

What Does “DNS Server Not Responding” Actually Mean?

Every time you type a website address into your browser, your device needs to translate that human-readable name (like google.com) into a numerical IP address that computers use to route traffic. That translation is handled by a DNS server, think of it as the internet’s phone book.

When you see “DNS server not responding,” it means your device sent that translation request and got no reply. The DNS server it was configured to use either didn’t respond in time, returned an error, or couldn’t be reached at all.

There are a handful of reasons this happens: your router’s DNS server may have gone down, your DNS cache may have gone stale or corrupted, a firewall may be blocking DNS traffic, or your ISP’s DNS infrastructure may simply be having problems. The fix depends on which of these is to blame – which is exactly what this guide helps you figure out.

Common DNS Error Codes and What They Mean

DNS problems show up under many different error messages depending on your browser and operating system. Here’s a quick reference for the ones we see most often.

All of these errors point to the same underlying problem, DNS resolution failed, so the fixes below apply to all of them.

Start Here: The Three Fastest Fixes

Before working through the full list, try these three first. They solve the problem in the majority of cases and take less than five minutes combined.

Quick Fix 1 – Flush Your DNS Cache

Your device stores recent DNS lookups in a local cache. If an entry has gone stale or corrupted, it causes resolution failures. Flushing it forces a fresh lookup.

Windows

ipconfig /flushdns

macOS (Monterey and later)

sudo dscacheutil -flushcache && sudo killall -HUP mDNSResponder

Linux (systemd)

sudo systemd-resolve --flush-caches

After running the command, reload the page you were trying to reach. If it still doesn’t load, move to Quick Fix 2.

Quick Fix 2 – Switch to a Public DNS Server

Your router or ISP may be assigning a DNS server that is slow, down, or unreliable. Switching to Google’s or Cloudflare’s public DNS is fast, free, and often resolves the issue immediately.

• Google DNS: 8.8.8.8 (preferred) and 8.8.4.4 (alternate)
• Cloudflare DNS: 1.1.1.1 (preferred) and 1.0.0.1 (alternate)

See the platform-specific section below for the exact steps on Windows, Mac, and Linux.

Quick Fix 3 – Restart Your Router

Many DNS errors are caused by the router itself having a stale or failed DNS state. Unplug it from the wall, wait a full 30 seconds, then plug it back in. Wait for it to fully reconnect before testing. This is a power cycle — not a factory reset — so nothing gets wiped.

All Fixes, Step by Step

If the quick fixes didn’t resolve it, work through the following in order. Each one addresses a different possible cause.

1. Try a Different Browser

Before going deeper, check whether the problem is browser-specific. Open a different browser and visit the same site. If it loads, the issue is with that browser’s DNS cache, not your system. In Chrome specifically, you can flush its internal DNS cache by going to chrome://net-internals/#dns and clicking “Clear host cache.”

2. Try a Different Device

Load the same website on another device on the same network it can be a phone, tablet, or another computer. If it works on the other device, the problem is specific to your machine. If every device on the network is affected, the problem is your router or your ISP’s DNS infrastructure.

3. Restart Your Computer

A restart clears transient network state, refreshes background services, and often resolves intermittent DNS failures caused by software conflicts. Worth doing before digging into more involved fixes.

4. Flush DNS Cache and Renew Your IP

On Windows you can flush the DNS cache and renew your IP address together, which helps if DHCP has assigned stale configuration.

Windows

ipconfig /flushdns
ipconfig /release
ipconfig /renew

macOS

sudo dscacheutil -flushcache && sudo killall -HUP mDNSResponder

Linux (systemd)

sudo systemd-resolve --flush-caches

5. Change Your DNS Server

Manually assigning a reliable public DNS server is one of the most effective fixes available. See the step-by-step instructions below for your operating system. Use 8.8.8.8 / 8.8.4.4 (Google) or 1.1.1.1 / 1.0.0.1 (Cloudflare).

6. Disable IPv6 Temporarily

Some DNS errors, particularly ERR_NAME_NOT_RESOLVED and “No functioning DNS server available”, are caused by a conflict between IPv6 and your DNS configuration. Temporarily disabling IPv6 can confirm whether this is the cause and often resolves it outright.

Windows: Control Panel ? Network and Sharing Center ? click your active connection ? Properties ? uncheck Internet Protocol Version 6 (TCP/IPv6) ? OK.

macOS: System Settings ? Network ? select your connection ? Details ? TCP/IP tab ? set “Configure IPv6” to Link-local only.

Linux:

sudo sysctl -w net.ipv6.conf.all.disable_ipv6=1

7. Check Your Firewall and Antivirus

DNS traffic uses port 53 (UDP and TCP). If your firewall or antivirus is blocking this port, DNS resolution will fail silently. Temporarily disable your firewall and check whether the error clears. If it does, add a specific exception for DNS traffic rather than leaving your firewall off.

Only disable your firewall long enough to test. Re-enable it as soon as you’ve confirmed whether it was the cause.

8. Disable Secondary Network Adapters

If your machine has multiple active network adapters, a physical Ethernet card, a Wi-Fi adapter, and a virtual adapter from VPN or virtual machine software, they can conflict during DNS resolution. Disabling adapters you’re not actively using can resolve these conflicts.

Windows: Control Panel ? Network Connections ? right-click any unused adapter ? Disable.

Linux:

sudo ip link set eth1 down

Replace eth1 with the interface you want to disable. Run ip link show to list all interfaces.

9. Disconnect Your VPN

VPNs route DNS queries through their own servers. If the VPN’s DNS infrastructure is down or misconfigured, you’ll get DNS errors even though the rest of your internet connection works fine. Disconnect your VPN and test again. If DNS resolves normally without it, the issue is with the VPN’s DNS settings.

10. Update Network Adapter Drivers (Windows)

Outdated or corrupted network adapter drivers can cause intermittent DNS failures, especially after a Windows update. Right-click the Start button ? Device Manager ? expand Network adapters ? right-click your adapter ? Update driver ? Search automatically for updated driver software.

11. Boot in Safe Mode with Networking

If you suspect a third-party application is interfering with DNS, some security tools and system utilities can do this, booting in Safe Mode with networking loads only essential services. If DNS works in Safe Mode, a startup application in your normal environment is the culprit.

Windows: Press Windows + R ? type msconfig ? Boot tab ? check Safe boot and select Network ? Apply ? restart.

Mac (Apple Silicon): Shut down, hold the power button until startup options appear, select your disk, hold Shift, then click Continue in Safe Mode.

Mac (Intel): Restart and hold the Shift key until the Apple logo appears.

How to Change Your DNS Server – Step by Step

Windows 10 and Windows 11

1. Press Windows + R, type ncpa.cpl, and press Enter.
2. Right-click your active network connection and select Properties.
3. Select Internet Protocol Version 4 (TCP/IPv4) and click Properties.
4. Select Use the following DNS server addresses.
5. Enter 8.8.8.8 as the Preferred DNS server and 8.8.4.4 as the Alternate.
6. Click OK, then close the remaining windows.

macOS (Ventura, Sonoma, and Later)

1. Open System Settings and go to Network.
2. Click your active connection (Wi-Fi or Ethernet), then click Details.
3. Go to the DNS tab.
4. Click the + button and add 8.8.8.8, then add 8.8.4.4.
5. Click OK and then Apply.

Ubuntu / Debian Linux

On modern Ubuntu (18.04 and later using systemd-resolved), open the resolved config:

sudo nano /etc/systemd/resolved.conf

Find the [Resolve] section and set the DNS line to:

DNS=8.8.8.8 8.8.4.4

Save the file and restart the resolver:

sudo systemctl restart systemd-resolved

On systems using /etc/resolv.conf directly, open the file and add or replace the nameserver lines:

nameserver 8.8.8.8
nameserver 8.8.4.4

How to Verify Your DNS Is Working

After applying a fix, use these commands to confirm DNS is resolving correctly.

Windows and macOS:

nslookup google.com

Linux:

dig google.com

A successful response returns a valid IP address. If you see NXDOMAIN, SERVFAIL, or a timeout, DNS is still not resolving correctly.

You can also quickly separate a DNS problem from a broader connectivity issue by pinging an IP address directly:

ping 8.8.8.8

If this succeeds but visiting websites doesn’t, the problem is definitively DNS. If this also fails, you have a broader network connectivity issue rather than a DNS-specific one.

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Frequently Asked Questions

What does “DNS server not responding” mean?

It means your device sent a request to translate a domain name into an IP address, and the DNS server did not reply. This can be caused by the DNS server being down, your network failing to reach it, a misconfigured router, or a corrupted local DNS cache.

What is the fastest fix for DNS server not responding?

Start by flushing your DNS cache, on Windows run ipconfig /flushdns, on Mac run sudo dscacheutil -flushcache && sudo killall -HUP mDNSResponder. If that doesn’t work, switch your DNS server to 8.8.8.8 and restart your router. These three steps resolve the majority of DNS errors.

Why does Windows say “Your DNS server might be unavailable”?

This message appears when the Windows network troubleshooter detects that your configured DNS server isn’t responding. It’s most commonly caused by your router’s DNS server going down or your ISP experiencing issues. Manually switching to Google DNS (8.8.8.8) typically fixes it immediately.

How do I fix DNS_PROBE_POSSIBLE in Chrome?

Go to chrome://net-internals/#dns and click “Clear host cache” to flush Chrome’s internal DNS cache. Then flush your system DNS cache, and if the error persists, switch your network adapter’s DNS to 8.8.8.8. This error means Chrome’s DNS probe returned an inconclusive result — a fresh lookup usually clears it.

How do I fix “No functioning DNS server available”?

This Windows error means none of the DNS servers in your configuration are responding. The most reliable fix is to go into your network adapter’s TCP/IPv4 properties and manually enter 8.8.8.8 as the preferred DNS and 8.8.4.4 as the alternate. This overrides whatever broken server your router was assigning automatically.

Is it safe to flush DNS?

Yes, completely. Flushing DNS clears your device’s cache of recently resolved domain names. No settings are changed, no data is deleted, and your internet connection isn’t interrupted. The cache rebuilds itself automatically as you browse.

How do I fix DNS errors on a Mac?

Open Terminal and run: sudo dscacheutil -flushcache && sudo killall -HUP mDNSResponder. If the error persists, go to System Settings ? Network ? select your connection ? Details ? DNS tab, and add 8.8.8.8 and 8.8.4.4. On macOS Monterey and later, the killall -HUP mDNSResponder part is required, dscacheutil alone won’t fully flush the cache.

How do I check if my DNS is working?

Run nslookup google.com in a command prompt or terminal. A working DNS returns a valid IP address. You can also run ping 8.8.8.8, if that succeeds but ping google.com fails, the problem is definitely DNS rather than general network connectivity.

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