What does 'DNS server not responding' mean?
Every time you visit a website, your device performs a silent lookup: it contacts a DNS (Domain Name System) server and asks "what is the IP address for this domain?" The DNS server translates the human-readable name (like example.com) into a numeric IP address your browser can connect to.
When you see "DNS server not responding" or the closely related "DNS server is not responding" error, it means that lookup failed. Your device sent a request to the DNS server and received no answer — either because the server is unreachable, overloaded, or your device is configured to use an address that doesn't exist.
Crucially, this is not the same as having no internet. You can have a perfectly working connection and still hit this error — because the translation layer between domain names and IP addresses is broken, not the connection itself.
How DNS resolution works (in plain English)
When you enter a URL, here is what happens in under 50 milliseconds on a healthy network:
- 1Your browser checks its own memory (in-process cache) for a recent answer.
- 2If nothing is cached, it asks the operating system, which checks its local DNS cache.
- 3If still no match, the OS queries the configured DNS resolver — usually your router or ISP.
- 4The resolver contacts the authoritative nameserver for the domain.
- 5The IP address is returned, cached, and your browser connects.
A dns problem can occur at any of these steps — a stale cache, a misconfigured resolver, a router that drops UDP packets on port 53, or an ISP outage. The error message is the same regardless of where the chain breaks.
Temporary vs. persistent errors
Before you start troubleshooting, it helps to know what kind of failure you are dealing with. Temporary errors usually clear up on their own or with a simple restart. Persistent errors require deliberate configuration changes.
| Type | Symptoms | Likely cause | First step |
|---|---|---|---|
| Temporary | Clears after a refresh or restart | Brief ISP outage, router reboot, Wi-Fi hiccup | Restart router; flush DNS cache |
| Persistent | Affects multiple browsers or devices | Wrong DNS settings, ISP DNS failure, firewall block | Switch to public DNS; check firewall |
| Site-specific | Only one domain fails | Stale cache, DNSSEC failure, domain expired | Flush cache; query with nslookup |
Common causes of DNS server not responding
The same dns server not responding message can be triggered by a dozen different root causes. Here are the most common, ranked from most to least likely for home and small-business users.
1. Router or modem problems
The router is the first DNS relay in most home networks. If it has overheated, crashed, or is running outdated firmware, DNS queries may never leave your local network. A stale DNS cache on the router can also cause repeated failures for specific domains. This is the most common cause of a network-wide dns problem where every device on the same Wi-Fi shows the same error.
2. ISP DNS server outage or hijacking
Your ISP assigns a DNS server automatically. If that server goes down, becomes overloaded, or is intercepting queries for ad injection, every device on your connection will show "dns server unavailable". Switching to a public resolver (see section 5) instantly confirms whether this is the cause.
3. Misconfigured DNS settings on your device
If you have ever manually entered a DNS address and made a typo, or if a VPN or network change left behind stale settings, your device will keep querying a server that does not exist. The error "dns server isn't responding" in this case is literally accurate — the address you configured is unreachable.
4. Firewall, antivirus, or VPN interference
Security software sometimes blocks DNS traffic on UDP port 53, or a VPN routes queries through its own resolver which may be unreachable. If the error disappears when you disable your VPN or firewall, one of these tools is the culprit.
5. Stale OS or browser DNS cache
Your operating system and browser both cache DNS results to speed up browsing. If a site's IP address changes and your cached entry is outdated, the connection will fail even though the DNS server itself is working fine. Flushing the cache (covered in the next section) fixes this immediately.
6. IPv6 misconfiguration
On dual-stack networks, your device may try IPv6 DNS first. If your router or ISP does not properly support IPv6, every lookup hangs until it times out and falls back to IPv4 — causing noticeable delays or outright failures. Temporarily disabling IPv6 on your network adapter is a quick diagnostic step.
7. Malware or a tampered hosts file
Some malware modifies your system's hosts file or DNS settings to redirect traffic to malicious servers. If you notice the error appearing alongside unusual browser behaviour (unexpected redirects, new toolbars), run a malware scan before changing any DNS settings.
Know before your users do
Alive24x7 monitors your DNS records 24/7 and alerts you the moment something changes or stops resolving — before it becomes a customer-facing outage.
Quick fixes for beginners
Work through these steps in order. Most dns server not responding errors are resolved by step 3 or 4.
Step 1 — Restart your router and device
Power-cycle your router and modem: unplug them from the wall, wait 30 seconds, then plug back in. While they reconnect, restart your computer or phone as well. This clears temporary state in both your device's DNS cache and the router's forwarding table. It fixes a surprising proportion of cases.
Step 2 — Test on a different browser and device
Open the same URL in a different browser (e.g. try Firefox if you were using Chrome). If it loads, the issue is browser-specific — clear the browser cache and DNS cache (see below). If the same error appears in every browser and on another device, the problem is network-wide, not browser-level.
Step 3 — Flush your DNS cache
Your OS stores DNS results locally. Outdated entries cause failures when a domain's IP address has changed. Flush the cache with the command for your platform:
ipconfig /flushdns
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
sudo systemd-resolve --flush-caches
After flushing, reopen your browser and retry. For Chrome specifically, you can also flush its internal DNS cache at chrome://net-internals/#dns.
Step 4 — Switch to a public DNS server
If your ISP's DNS is the problem, switching to a public resolver fixes it instantly. The most reliable options are:
| Provider | Primary DNS | Secondary DNS | Strengths |
|---|---|---|---|
| Cloudflare | 1.1.1.1 | 1.0.0.1 | Fastest globally, privacy-first, no query logging |
| 8.8.8.8 | 8.8.4.4 | Extremely reliable, global anycast network | |
| Quad9 | 9.9.9.9 | 149.112.112.112 | Blocks known malicious domains, privacy-focused |
On Windows: Control Panel → Network and Internet → Network and Sharing Center → Change adapter settings → right-click your connection → Properties → Internet Protocol Version 4 (TCP/IPv4) → Properties → enter the DNS addresses above.
On macOS: System Settings → Network → select your active connection → Details → DNS tab → click + and add the addresses.
Step 5 — Temporarily disable IPv6
If your network supports IPv6 but your router or ISP does not handle it cleanly, DNS lookups can stall. On Windows, open the same adapter Properties dialog and uncheck Internet Protocol Version 6 (TCP/IPv6). On macOS, go to Network → Details and set IPv6 to Off. Test again — if the error disappears, your IPv6 configuration needs attention.
Advanced troubleshooting
If the quick fixes above did not resolve the issue, use these diagnostic tools to pinpoint exactly where resolution is failing.
Use nslookup to query DNS directly
nslookup is available on Windows, macOS, and Linux. It lets you query any DNS server directly and see exactly what it returns.
# Query your default DNS server nslookup example.com # Query a specific public DNS server (bypasses your ISP) nslookup example.com 8.8.8.8 # If the first times out but the second works → your default DNS is the problem
A SERVFAIL response means the resolver could not complete the lookup. NXDOMAIN means the domain does not exist. A timeout with no response confirms the server is unreachable.
Use dig for deeper inspection (macOS / Linux)
# Full DNS resolution trace dig example.com # Check a specific record type dig MX example.com dig NS example.com # Query a specific server with verbose output dig @1.1.1.1 example.com +stats
Focus on the ANSWER SECTION and the Query time. A query time above 200ms suggests latency at the resolver. No answer section at all confirms the dns server is not responding.
Confirm it is DNS and not the network
# Ping an IP address directly (bypasses DNS entirely) ping 8.8.8.8 # If this works but pinging a domain name fails, DNS is definitely the issue ping google.com
Inspect and reset the hosts file
Your system's hosts file overrides DNS for specific domains. Malware or misconfigured software sometimes adds entries that redirect or block domains. Open the file with administrator privileges and look for unexpected entries.
| OS | Hosts file path |
|---|---|
| Windows | C:\Windows\System32\drivers\etc\hosts |
| macOS / Linux | /etc/hosts |
A clean hosts file should contain only 127.0.0.1 localhost and ::1 localhost. Remove any other entries you did not add intentionally.
Check DNS over HTTPS (DoH) settings
Modern browsers can encrypt DNS queries using DNS over HTTPS. If the DoH provider is unreachable, the browser shows a DNS error even though system DNS works fine. In Chrome, go to Settings → Privacy and security → Security → Use secure DNS and try disabling it temporarily. In Firefox, Settings → General → Network Settings → Enable DNS over HTTPS.
Diagnostic tools reference
| Tool | Platform | What it tells you | Best for |
|---|---|---|---|
| nslookup | All | Which server responded and what IP it returned | Confirming DNS resolution works |
| dig | macOS / Linux | Full resolution chain, record types, query time | Deep DNS inspection |
| ping (IP) | All | Whether the network itself is working | Ruling out network issues |
| traceroute / tracert | All | Where packets are being dropped or delayed | Identifying routing problems |
| Wireshark | All | Raw DNS packets on the wire | Intermittent or hard-to-reproduce failures |
How to fix DNS errors by device and OS
The underlying dns problem is the same across platforms, but the steps to fix it differ. Find your device below.
Windows 10 / 11
Windows shows the error as "DNS server isn't responding" in the network troubleshooter, or "This site can't be reached" in the browser.
- 1Open an elevated Command Prompt and run: ipconfig /flushdns
- 2Restart the DNS client service: net stop dnscache && net start dnscache
- 3Change DNS: Control Panel → Network and Sharing Center → Change adapter settings → right-click your connection → Properties → IPv4 → Use the following DNS server addresses → enter 1.1.1.1 and 8.8.8.8
- 4If still failing, reset TCP/IP: netsh int ip reset && netsh winsock reset, then reboot
macOS (Ventura / Sonoma)
- 1Flush DNS cache: sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
- 2Change DNS: System Settings → Network → select your connection → Details → DNS tab → remove existing entries → add 1.1.1.1 and 8.8.8.8 → Apply
- 3If on Wi-Fi, toggle it off and on, or forget the network and reconnect
- 4Check System Preferences → Security & Privacy → Firewall to ensure DNS traffic is not blocked
Linux (systemd-resolved)
- 1Flush cache: sudo systemd-resolve --flush-caches
- 2Check current resolver: systemd-resolve --status | grep "DNS Servers"
- 3Edit /etc/systemd/resolved.conf and add DNS=1.1.1.1 8.8.8.8, then restart: sudo systemctl restart systemd-resolved
- 4Check logs for errors: journalctl -u systemd-resolved -n 50
iOS (iPhone / iPad)
- 1Settings → Wi-Fi → tap the ⓘ next to your network → Configure DNS → Manual
- 2Remove existing entries and add 1.1.1.1 and 8.8.8.8
- 3Toggle Airplane Mode on and off to force a fresh DNS connection
- 4For cellular data, use Cloudflare's 1.1.1.1 app to override carrier DNS
Android
- 1Settings → Network & Internet → Wi-Fi → long-press your network → Modify network
- 2Change IP settings to Static and set DNS 1 = 1.1.1.1, DNS 2 = 8.8.8.8
- 3For Android 9+: Settings → Network & Internet → Private DNS → enter one.one.one.one (Cloudflare DoT)
- 4For mobile data, use a DNS-over-TLS app or VPN to override carrier DNS
Router (all devices on the network)
Changing DNS on the router is the most efficient fix when the error affects every device on your network.
- 1Log in to your router admin panel (usually 192.168.0.1 or 192.168.1.1)
- 2Find DNS settings under WAN, Internet, or DHCP settings
- 3Replace ISP-assigned DNS with 1.1.1.1 (primary) and 8.8.8.8 (secondary)
- 4Save and reboot the router — all devices on the network will use the new DNS immediately
- 5If the router has a DNS cache, clear it or reboot to force fresh lookups
Choosing the best DNS server
Not all DNS servers perform equally. The right choice depends on your priorities: raw speed, privacy, or security filtering. Here is a practical comparison of the most widely used public resolvers.
| Provider | Primary | Privacy | Security filtering | Supports DoH / DoT |
|---|---|---|---|---|
| Cloudflare | 1.1.1.1 | No identifying logs, independently audited | No (use 1.1.1.2 for malware filtering) | Yes |
| 8.8.8.8 | Temporary logs (24–48 hrs) | No | Yes | |
| Quad9 | 9.9.9.9 | No data monetisation | Yes — blocks known malicious domains | Yes |
| OpenDNS | 208.67.222.222 | Logs queries | Yes — customisable filtering | Yes |
To find the fastest resolver from your specific location, run a benchmark before committing. On macOS and Linux, use dig to compare response times:
dig @1.1.1.1 example.com | grep "Query time" dig @8.8.8.8 example.com | grep "Query time" dig @9.9.9.9 example.com | grep "Query time"
Pick the one with the lowest query time. For Windows, the free tool DNS Benchmark by GRC tests dozens of resolvers from your network and ranks them by speed and reliability.
Prevention and ongoing DNS monitoring
Fixing a dns server not responding error reactively is fine once. Doing it repeatedly is a sign that something in your setup needs a permanent fix — and if you run a website or service, DNS failures affect your users before you even know about them.
1. Configure redundant DNS servers
Always set both a primary and a secondary DNS server. If the primary is unreachable, your device automatically falls back to the secondary. Using two different providers (e.g. Cloudflare as primary and Google as secondary) means a single provider outage does not affect you at all.
2. Keep DNS records clean and up to date
If you manage a domain, audit your DNS records regularly. Remove stale A, CNAME, and MX records that point to decommissioned servers. Set appropriate TTL values — lower TTLs mean faster propagation when you need to make changes, but higher TTLs reduce resolver load under normal conditions.
3. Enable DNSSEC and encrypted DNS
DNSSEC adds cryptographic signatures to DNS responses, preventing tampering and spoofing. DNS over HTTPS (DoH) and DNS over TLS (DoT) encrypt the queries themselves, preventing interception. Both are supported by all major public resolvers and most modern operating systems.
4. Monitor your DNS records automatically
DNS failures are often silent — your records change unexpectedly, a nameserver goes down, or a misconfiguration propagates across the internet before anyone notices. By the time a user reports the issue, it has already been affecting your site for minutes or hours.
Alive24x7 monitors your DNS records continuously. If a record stops resolving, changes to an unexpected value, or a nameserver becomes unreachable, you receive an instant alert by email, Slack, or SMS — before your users encounter the problem.
Know before your users do
Alive24x7 monitors your DNS records 24/7 and alerts you the moment something changes or stops resolving — before it becomes a customer-facing outage.
Frequently asked questions
Summary
A dns server not responding error is almost always fixable. Start by restarting your router and flushing your DNS cache. If that does not work, switch to a public resolver like Cloudflare (1.1.1.1) or Google (8.8.8.8). For persistent issues, use nslookup or dig to isolate exactly where resolution is failing.
If you manage a website or service, proactive DNS monitoring with Alive24x7 means you find out about DNS failures before your users do — with instant alerts and a full history of what changed and when.
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