Trying to open your favorite website or check your email, only to see the error "DNS server unavailable" instead of the usual page, can be frustrating for anyone. This message means your device is connected to the router but can't resolve the domain name to the IP address needed to connect to the internet. Essentially, your computer or smartphone has "forgotten" where to go to access the resource you need.
The problem could be due to a software glitch in the operating system or incorrect router settings. Often, temporary outages at the ISP or a corrupted DNS cache on the local device are the cause. Don't panic: in most cases, access restoration It only takes a few minutes if you know which controls to use.
In this article, we'll examine all possible causes of the error and provide step-by-step solutions for Windows, Android, and iOS. We'll cover both simple methods like rebooting and more complex network protocol manipulations. Understanding how it works Domain Name System, will help you not only fix the current failure, but also prevent it from occurring in the future.
Primary diagnostics and simple reboot of equipment
Before delving into the complex settings of network adapters, it's important to rule out simple hardware failures. Routers, like any other computer devices, have limited RAM and processors, which can overheat or freeze during prolonged operation. The accumulation of temporary errors in the data exchange buffer often leads to The DNS server stops responding. to customer requests.
The first thing you need to do is perform a full reboot of the entire equipment chain. Turn off your computer or smartphone, then unplug the router and modem. Wait 10-15 seconds for the capacitors to discharge, and then turn on all devices again, starting with the modem. This sequence of actions allows the equipment to properly establish a connection with the provider before distributing the internet.
If the problem persists after a reboot, it's worth checking the physical condition of the cables. A damaged twisted pair cable or a poor connection in the connector can cause packet loss, which the system interprets as name server unavailability. Also, check the indicators on the front panel of the router: if the red indicator is lit, Internet or WAN, the problem may be on the provider's side.
Automatic and manual obtaining of IP and DNS addresses
The most common cause of this error is a conflict between the static settings specified in the operating system and the current network configuration. If a DNS server address is manually specified in the network adapter properties and it is no longer functioning or has changed, internet access will be blocked. In such cases, you should reset the settings to automatic.
For Windows users, the solution is through the Network Connections control panel. Press the following key combination: Win + R, enter the command ncpa.cpl and press Enter. In the window that opens, find your wireless connection, right-click on it, and select "Properties." Next, find the protocol in the list. Internet Protocol version 4 (TCP/IPv4) and also open its properties.
In the window that opens, make sure the boxes next to "Obtain an IP address automatically" and "Obtain DNS server address automatically" are checked. If any numbers were previously entered there, deleting them and switching to automatic mode often resolves the issue immediately. After applying the settings, it's recommended to update the configuration via the command line.
☑️ Check TCP/IP settings
In some cases, automatic data retrieval fails due to a DHCP service freeze on the router. In this situation, you can try manually entering public DNS addresses from Google or Cloudflare. This will bypass the local failure and redirect requests to reliable external servers.
⚠️ Important: When manually entering DNS addresses, make sure you enter the numbers correctly. An incorrect address will result in complete loss of access to network resources, even if you are technically connected to the router.
Reset network settings and clear DNS cache
Operating systems actively cache DNS queries to speed up network performance. However, over time, this cache can accumulate stale or corrupted records, which interfere with proper name resolution. If you see the "DNS server unavailable" error, clearing the cache is a necessary diagnostic step.
To perform this procedure in Windows, launch the Command Prompt as an administrator. You can do this by finding "Command Prompt" in the Start menu, right-clicking, and selecting the appropriate option. In the black terminal window, enter the command ipconfig /flushdns and press Enter. The system will confirm that the resolver cache has been cleared successfully.
ipconfig /flushdnsipconfig /registerdns
ipconfig /release
ipconfig /renew
In addition to clearing the cache, it's a good idea to re-register the DNS and update the IP address, as shown in the code block above. Running these commands sequentially will completely update the adapter's network configuration. For macOS users, the command looks different: sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder.
What to do if the command prompt does not open?
If you don't have administrator rights or the Start menu is unresponsive, try pressing Win+X and selecting Windows PowerShell (Admin) or Terminal. On some corporate networks, access to the command prompt may be blocked by security policies, in which case you'll need to contact your system administrator.
Setting up alternative DNS servers
If your provider's default servers are unstable or blocked, it makes sense to switch to public alternatives. Market leaders in this area include Google Public DNS and Cloudflare, which provide high response speeds and reliability. Using third-party DNS often solves the "server not responding" problem.
To configure in Windows, return to the protocol properties IPv4, which we discussed earlier. Select "Use the following DNS server addresses." In the "Preferred" and "Alternate" fields, enter the addresses of the selected services. For example, for Google, this is 8.8.8.8 And 8.8.4.4, and for Cloudflare - 1.1.1.1 And 1.0.0.1.
On mobile devices, the process is slightly different. On Android, you need to go to Wi-Fi settings, press and hold your network name, select "Edit network," expand advanced settings, and enter the new values in the DNS 1 and DNS 2 fields. On iOS, the process is Settings → Wi-Fi → (blue letter i) → DNS Configuration → Manual.
Below is a table of popular free DNS services that can be used as a replacement:
| DNS provider | Main address | Alternative address | Peculiarities |
|---|---|---|---|
| Google Public DNS | 8.8.8.8 | 8.8.4.4 | High speed, global coverage |
| Cloudflare | 1.1.1.1 | 1.0.0.1 | Focus on privacy and speed |
| OpenDNS | 208.67.222.222 | 208.67.220.220 | Built-in phishing protection |
| Quad9 | 9.9.9.9 | 149.112.112.112 | Blocking malicious domains |
Error handling on mobile devices
Smartphone and tablet owners also often encounter a situation where Wi-Fi is connected, but the internet is down due to DNS issues. Networking mechanisms are similar on Android and iOS, but the settings interfaces differ. Often, the problem is resolved by simply forgetting the network and reconnecting with the password.
If reconnecting doesn't help, try disabling the "Private DNS" feature in Android settings if it's enabled. This feature, introduced in Android 9 and later, encrypts DNS requests but may conflict with some routers or antivirus software. Here's how to set it up: Settings → Connections → Other Settings → Private DNS (select Auto or Off).
On Apple devices, resetting network settings can sometimes help. This will delete all saved Wi-Fi passwords and Bluetooth settings, but will return the network settings to factory defaults. Path: Settings → General → Transfer or reset iPhone → Reset → Reset Network SettingsAfter rebooting, the device will attempt to receive clear settings from the router.
Why does mobile internet work on my phone, but not Wi-Fi?
This indicates that the problem is localized within the local network or router, not the device itself. Mobile data uses the cellular operator's gateways, bypassing the problematic DNS of your home router.
Resetting the router to factory settings
When software solutions on your computer or phone fail, the problem may lie in the router's configuration. Complex settings, firmware changes, or software errors can cause the device to stop correctly transmitting DNS requests. In this case, a hard reset is an effective solution.
To perform a reset, find the button on the router body. Reset or RestoreIt's usually recessed into the housing to prevent accidental pressing. You'll need a thin object, such as a paperclip. Press and hold the button on the powered-on router for 10-15 seconds until all the lights flash simultaneously. After this, the device will reboot to factory settings.
⚠️ Warning: A full router reset will erase all your settings, including the Wi-Fi network name, password, and PPPoE/L2TP settings from your ISP. Be prepared to reconfigure your router for internet access.
After the reset, you need to re-enter the router's web interface (usually at the address 192.168.0.1 or 192.168.1.1) and run the quick setup wizard. Make sure the correct connection type required by your ISP is selected in the WAN section. Often, after a reset, the router automatically detects the connection type, but in rare cases, manual intervention is required.
If the "DNS server unavailable" error persists even after resetting and reconfiguring, there's a high probability of a hardware fault with the router or a problem with the ISP's line. In this situation, it's worth calling your ISP's technical support and asking them to check the line remotely.
Why does the error only appear on one device?
If the internet is not working on just one specific laptop or phone, while other devices on the network are functioning normally, the problem lies in the settings of that specific device. Most likely, it has a static DNS that has stopped working, or an antivirus program is blocking network requests. Check the adapter settings on that specific device.
Can antivirus block DNS?
Yes, some antivirus protection features (such as Network Protection or Web Control) may mistakenly block DNS requests, deeming them suspicious. Try temporarily disabling your antivirus or its firewall to see if the error resolves.
What to do if the red light on the router is on?
A red light (often labeled "Internet," "WAN," or "Globe") indicates a physical connection to the ISP is missing. In this case, changing DNS addresses won't help. Check your ISP cable, make sure it's securely plugged into the WAN port, and contact your ISP's technical support to check the status of your contract and line.
How to check if the DNS server is working?
The easiest way to check is to use the ping command in the command line. Enter ping 8.8.8.8If there is a response (packets are coming), then there is an internet connection. Then enter ping google.comIf the IP can be pinged, but the domain name can't, the problem is definitely with the DNS.