DNSサーバーが応答しない？あらゆるデバイスで修正する方法
DNSエラーの原因、その迅速な解決方法、そしてプライバシーツールを使ってDNSトラフィックを保護する方法について学びましょう
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ウェブサイトを読み込もうとした際に、「DNSサーバーが応答していません」というエラーメッセージが表示された経験はありませんか？これは苛立たしいことですが、驚くほどよく見られる現象です。
しかし、さらに重要なのは、DNSの設定ミスが接続を中断させたり、セキュリティ上の脆弱性を招いたりする可能性があることです。特に、VPNやプロキシなどのプライバシーツールを使用していない場合はなおさらです。
このガイドでは、DNSとは何か、「DNSサーバーが応答しません」というエラーが発生する理由、さまざまなデバイスでの解決方法、そしてNymVPNのようなVPNを使用することで、DNSに関連するリスクを未然に防ぐ方法についてご説明します。
What is DNS and why does it matter?
DNS stands for Domain Name System. It's like the internet’s phonebook: when you type a web address like nym.com, DNS servers translate it into the IP address your device actually needs to connect.
Without DNS, you'd have to memorize long strings of numbers like 104.26.5.116 instead of just typing a URL.
But here’s the catch: not all DNS servers are reliable or safe. Your DNS queries can be logged, redirected, or blocked by:
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Your Internet Service Provider (ISP)
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Public Wi-Fi networks
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Malicious third-party servers
DNS設定を改善するか、あるいは家庭用VPNを利用することで、高速で安定したアクセスを維持し、望ましくない接続障害を回避することができます。
Why you’re getting “DNS Server Not Responding”
This error means your browser or device can’t get a response from the DNS server it's trying to use. Some common causes include:
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Temporary internet outages or weak connections that prevent your device from reaching the DNS server
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DNS settings that are outdated or manually entered incorrectly, leading to failed lookups or no response at all
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Malfunctioning routers or outdated network adapters that drop DNS requests before they reach the server
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Firewall or antivirus software settings that mistakenly block DNS traffic as a security precaution
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Public DNS servers that are overloaded and unable to respond in time
While some problems are temporary, others require you to manually update your settings or switch DNS providers.
Quick fixes for “DNS Server Not Responding”
If you’re seeing the “DNS server not responding” error, the good news is it’s often easy to fix. Below are some quick steps you can try. We'll start with the simplest solutions and move toward more advanced troubleshooting if needed.
Power-cycling clears temporary connection bugs.
See if the issue is browser-specific.
If you’re not using a residential VPN, some software may block DNS traffic.
Windows: Open Command Prompt and run ( ipconfig /flushdns )
Mac: Open Terminal and run: ( sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder )
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Google DNS: 8.8.8.8 and 8.8.4.4
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Cloudflare DNS: 1.1.1.1 and 1.0.0.1
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OpenDNS: 208.67.222.222 and 208.67.220.220
Or, use a VPN with private DNS routing for added protection and consistency.
How to change DNS settings on different devices
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Go to Settings > Wi-Fi
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Tap the ⓘ next to your network
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Tap Configure DNS > Manual
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Add your preferred DNS servers (e.g., 1.1.1.1)
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Go to Settings > Network & Internet > Wi-Fi
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Tap your network > Advanced
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Set IP settings to Static, then enter DNS fields
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Open System Settings > Network > Wi-Fi
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Select your network and tap Details
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Scroll to the DNS section and enter your servers
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Open Settings > Network & Internet
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Click your connection > Edit IP assignment > Manual
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Toggle IPv4 and enter your DNS addresses
What are DNS leaks and why should you care?
Even with the right settings, your device might still leak DNS queries. A DNS leak happens when your DNS requests bypass your secure setup and go straight to your ISP — or worse.
This often happens when:
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A VPN doesn’t securely route DNS traffic
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Your OS overrides DNS preferences
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An app (like a browser) uses its own DNS service
To test your setup, visit dnsleaktest.com. If it shows your ISP or a strange provider, you're leaking.
NymVPN includes DNS leak protection by default, helping ensure your requests don’t end up in the wrong hands.
Devices can store old or misconfigured network settings that interfere with DNS.
iPhone & Android: Forget unused Wi-Fi networks in Settings.
Mac: Go to Wi-Fi > Known Networks and remove old ones.
Windows: Use ( netsh wlan show profiles ) in Command Prompt to list and delete outdated profiles.
A clean setup improves reliability and minimizes connection conflicts.
How a VPN helps with DNS reliability
VPNs that include private DNS routing can:
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Encrypt DNS traffic so that it can’t be read, logged, or intercepted by your ISP, Wi-Fi providers, or third parties.
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Stop DNS hijacking or spoofing attempts, where attackers redirect your queries to fake sites over unsecured networks.
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Bypass censorship or ISP filtering that may block content at the DNS level.
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Avoid logging by your ISP or third parties, helping you maintain more consistent access and security.
With NymVPN, DNS requests are made to look like regular traffic and reduce blocks, tracking, or errors.
If none of the above works, try:
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Resetting your network settings
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Updating router firmware
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Testing another DNS provider
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Using a VPN like NymVPN to avoid local DNS entirely
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Contacting your ISP (as a last resort)
And for more on what your connection reveals, check out Nym's guides below to how to protect your privacy online from all untrusted third parties.
DNS: Frequently Asked Questions
A DNS (Domain Name System) address is like the contact name in your phone, while an IP address is like the phone number. When you enter a website’s name — like nym.com — your device uses DNS to look up the actual IP address, such as 104.26.5.116, so it can connect. This process happens instantly, but if DNS fails, your browser won’t know where to go. That's why DNS errors can feel like the internet is broken.
Yes, sometimes. If your default DNS server (usually set by your ISP) is overloaded or slow, switching to a public DNS provider like Cloudflare or Google can improve speed. However, the improvement is typically in how fast sites start to load, not how fast your internet downloads content. Using a VPN with optimized DNS, like NymVPN, can also provide consistent performance while maintaining privacy.
If web pages aren’t loading but apps like Zoom or email still work, it might be a DNS issue. You can test this by typing an IP address directly into your browser. For example, try visiting http://142.250.72.14 (a Google IP). If that works but google.com doesn’t, your DNS isn’t resolving correctly. Switching DNS servers or restarting your router can often fix this.
About the authors
Benjamin Nemeroff
Casey Ford. PhD
Technical reviewer目次
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