DNS Server Not Responding: How to Diagnose and Fix It Quickly

DNS Server Not Responding: Common Causes and Easy Solutions

The DNS server not responding error is one of the most common internet connectivity issues faced by users, developers, and IT teams alike. When this error occurs, websites fail to load, applications cannot connect to backend services, and overall webpage availability is impacted, even when the internet connection appears active.

From VergeCloud’s perspective, DNS issues are often misunderstood. While users may assume the website or server is down, the real problem usually lies in how domain names are being resolved. This article explains what the error means, why it occurs across different devices and networks, and how to fix it efficiently. We’ll also cover preventive strategies using modern DNS practices, including cloud DNS service, DNS load balancing serviceanycast network, and DNSSEC.

What is the “DNS server not responding” error? 

The DNS server not responding error occurs when your device cannot receive a valid response from the DNS server responsible for translating domain names into IP addresses.

In simple terms:
  1. DNS converts example.com into an IP address like 192.0.2.1
  2. Your browser or app sends a query to a DNS server
  3. If the DNS server fails to respond, the connection stops there
Even if:
  1. Your internet connection is active
  2. The website’s server is running
  3. Other sites load correctly

A DNS failure prevents the request from reaching the destination.

This error may appear as:

  1. “DNS server not responding”
  2. “Server DNS address could not be found”
  3. “This site can’t be reached”

Common causes of the “DNS server not responding” error 

DNS failures can originate from the client side, the network, or the DNS infrastructure itself. Below are the most common causes observed by VergeCloud’s network and support teams.

1. DNS server outage or overload

Public or ISP-provided DNS servers may become overloaded or temporarily unavailable, especially during traffic spikes or regional outages.

2. Network or router issues

Incorrect router settings, firmware bugs, or local network congestion can interrupt DNS queries, leading to failures on Wi-Fi connections.

3. Device-specific DNS cache problems

Corrupt or outdated DNS cache entries can cause resolution failures on individual devices, even when DNS works elsewhere.

4. Firewall or security software interference

Firewalls, VPNs, or overly strict DNS security settings can block DNS traffic (UDP/TCP port 53).

5. Misconfigured domain settings

Issues such as incorrect subdomain NS delegation or missing DNS records can cause partial or complete resolution failures.

6. Lack of redundancy in DNS architecture

Single-point DNS setups without DNS load balancing service or an anycast network are more prone to downtime.

How to Fix the “DNS server not responding” Error 

Below are the recommended troubleshooting steps, organized as H3 sections, applicable across operating systems and network types.

Restart Your Router and Modem 

This is the fastest and simplest fix for DNS server not responding on Wi-Fi.

Why it works:

  1. Clears temporary network glitches
  2. Resets DNS forwarding settings
  3. Re-establishes ISP DNS connectivity

Steps:

  1. Power off the router and modem
  2. Wait 30–60 seconds
  3. Power them back on
  4. Retry accessing the website

Flush the DNS Cache 

Flushing the DNS cache removes outdated or corrupted DNS entries stored locally.

On Windows 10:
ipconfig /flushdns
This step is particularly effective for DNS server not responding on Windows 10, where stale cache entries are a common issue.

Change DNS Servers Manually 

Switching from ISP-provided DNS to a reliable cloud DNS service can immediately resolve the issue.

Recommended options:
  1. Public DNS providers
  2. DNS platforms like VergeCloud DNS

Benefits include:

  1. Faster query resolution
  2. Improved reliability
  3. Better protection against outages

Check DNS Settings on Windows 10 

For users experiencing DNS server not responding on Windows 10, misconfigured adapter settings are often the cause.

What to verify:
  1. DNS is set to automatic or valid manual servers
  2. No legacy VPN or proxy DNS entries remain
  3. IPv4 and IPv6 settings are consistent

Fix DNS Server Not Responding on Mobile 

Mobile networks rely on carrier-managed DNS servers, which can be inconsistent.

Steps to try:
  1. Toggle airplane mode on and off
  2. Switch between mobile data and Wi-Fi
  3. Manually configure DNS if supported (Android)
  4. Restart the device

Mobile devices are especially sensitive to DNS latency and packet loss, which is why globally distributed DNS via an anycast network performs better.

Troubleshoot DNS Server Not Responding on Wi-Fi 

When DNS fails only on Wi-Fi but works on mobile data, the issue is almost always local.

Check for:
  1. Router DNS misconfiguration
  2. Firmware updates
  3. Parental control or firewall DNS blocking
  4. Incorrect DHCP DNS assignments

Run a Server Health Check 

From a website owner’s perspective, the issue may be on the authoritative DNS side.

A proper server health check should confirm:

  1. DNS servers are reachable
  2. Name servers are responding correctly
  3. Records are propagated globally
  4. No DNSSEC validation errors exist

At VergeCloud, automated health checks continuously monitor DNS availability to prevent resolution failures.

Verify Domain and Subdomain NS Configuration 

Incorrect subdomain NS records can break resolution for specific services like APIs, mail, or apps.

Common mistakes include:
  1. Delegating a subdomain without proper records
  2. Mixing multiple DNS providers incorrectly
  3. Missing glue records

Temporarily Disable VPN or Firewall 

Some VPNs and endpoint security tools intercept DNS traffic.

Temporarily disabling them helps confirm whether DNS filtering is the root cause. If confirmed, configure trusted DNS servers explicitly.

How to prevent the “DNS server not responding” Error 

Preventing DNS issues requires a proactive approach and reliable DNS infrastructure. From VergeCloud’s perspective, prevention is where most organizations gain long-term stability.

1. Use a reliable cloud DNS service

A globally distributed cloud DNS service reduces dependency on local or ISP DNS servers and ensures faster resolution across regions.

2. Implement DNS load balancing

A DNS load balancing service distributes queries across multiple servers, preventing overload and eliminating single points of failure.

3. Leverage an anycast network

An anycast network routes DNS queries to the nearest available node, improving performance and resilience during outages or traffic spikes.

4. Enable DNSSEC

DNSSEC protects DNS responses from spoofing and cache poisoning. While it does not prevent outages, it ensures data integrity and trust.

5. Monitor webpage availability continuously

DNS monitoring should be part of your webpage availability strategy. Detecting DNS failures early prevents prolonged downtime and user impact.

6. Regularly review DNS configurations

Periodic audits of DNS records, subdomain NS delegation, and TTL values help prevent misconfigurations that lead to resolution failures.

FAQ

1. Can a slow internet connection cause a DNS server not responding error?
Yes. High latency, packet loss, or unstable connections can prevent DNS queries from completing successfully, even if the DNS server itself is healthy.

2. Is it necessary to flush the DNS cache when troubleshooting DNS errors?
In many cases, yes. Flushing the cache removes stale entries and forces fresh DNS lookups, which often resolves client-side DNS issues.

3. Can DNS security settings affect connectivity?
Yes. Incorrect DNSSEC configuration, firewall rules, or overly strict DNS filtering can block legitimate DNS responses and cause resolution failures.

4. Are mobile networks more prone to DNS server issues than wired connections?
Mobile networks can be more susceptible due to roaming, signal changes, and carrier-managed DNS servers. Using a resilient DNS architecture helps mitigate this.
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