How to Refresh DNS: Local DNS Cache Vs Router DNS Cache for Troubleshooting Resolution

Posted on the 15 October 2026 by Pranav Rajput @PROnavrajput

Refresh your local DNS cache first, then restart or clear your router DNS cache if the problem affects more than one device. That is the fastest fix for most “website not loading” drama. Your computer keeps DNS answers in memory, and so does your router in many home networks. Windows even has a built-in command, ipconfig /flushdns, that clears the DNS resolver cache [source: Microsoft].

TLDR: DNS is like a phone book for websites. If your laptop has an old entry, flush the local DNS cache. If your whole house cannot reach the same site, refresh the router DNS cache or reboot the router. Example: if 1 laptop out of 5 fails to open example.com, fix the laptop; if 5 out of 5 fail, blame the router or DNS provider first.

What “refresh DNS” really means

When you type a website name, your device asks, “Where does this live?” DNS answers with an IP address. That answer may be saved for a while. This is called caching.

Caching is usually great. It makes pages load faster. It reduces repeated DNS lookups. It keeps the internet from asking the same question 500 times before lunch.

But cached DNS can get stale. A website may move to a new server. A domain may change records. Your VPN may alter DNS settings. Then your device keeps calling the old address. Honestly, it feels like yelling at a map from 2009.

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Local DNS cache vs router DNS cache

Think of DNS like asking for directions.

  • Local DNS cache: The directions saved on your laptop, phone, or desktop.
  • Router DNS cache: The directions saved by your Wi Fi router.
  • External DNS resolver: The bigger helper, such as your ISP, Google DNS, Cloudflare, or Quad9.

Your device may ask its own cache first. If it has no answer, it asks the router. The router may answer from its cache or ask another DNS server. Each layer can be useful. Each layer can also be wrong. Great. Thanks, computers.

When to refresh the local DNS cache

Start here if the issue is limited to one device. This is the cleanest test. It takes seconds.

Use a local DNS refresh when:

  • One computer cannot open a site, but your phone can.
  • A site works on mobile data, but not on your laptop.
  • You recently changed a domain record.
  • You switched VPNs.
  • You changed DNS servers on one device.
  • A browser says DNS_PROBE_FINISHED_NXDOMAIN.

The annoying part is that browsers may also keep their own DNS cache. So you might flush the operating system cache and still get the same error. It can cost 30 extra seconds and a bit of patience.

How to refresh local DNS cache

On Windows:

  1. Open Command Prompt as admin.
  2. Type ipconfig /flushdns.
  3. Press Enter.
  4. Look for a success message.

On macOS:

  1. Open Terminal.
  2. Run: sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
  3. Enter your password.
  4. Try the site again.

On Linux:

Linux varies. That is fun in the same way a drawer full of mystery cables is fun.

  • For systemd-resolved: sudo resolvectl flush-caches
  • For nscd: sudo systemctl restart nscd
  • For dnsmasq: sudo systemctl restart dnsmasq

For browsers:

  • Restart the browser.
  • Try a private window.
  • Clear browser cache if needed.
  • In Chrome, try chrome://net-internals/#dns if available in your version.

When to refresh the router DNS cache

Refresh the router DNS cache when multiple devices fail in the same way. That is the big clue. If your laptop, tablet, smart TV, and phone all fail on Wi Fi, your router may be holding bad DNS data.

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Use a router DNS refresh when:

  • All devices on Wi Fi cannot reach the same site.
  • The site works on mobile data.
  • Your router was recently updated.
  • You changed ISP DNS, Google DNS, or Cloudflare DNS.
  • Smart devices keep failing after one site or service changed servers.

Many consumer routers do not give you a shiny “clear DNS cache” button. Of course they don’t. That would be too nice. The usual fix is a restart.

How to refresh router DNS cache

  1. Save open work first.
  2. Unplug the router power cable.
  3. Wait 30 to 60 seconds.
  4. Plug it back in.
  5. Wait until Wi Fi returns.
  6. Test the website again.

You can also log in to the router admin page. Look for options like Reboot, Restart, DNS settings, or LAN settings. Some routers show DNS cache tools. Many do not.

If you use a separate modem and router, restart both. Power on the modem first. Wait until it is fully online. Then power on the router.

Quick test: local problem or router problem?

Use this simple test. No lab coat needed.

  1. Try the site on the broken device.
  2. Try the same site on another device using the same Wi Fi.
  3. Try the site on your phone using mobile data.
  • Only one device fails: Flush local DNS.
  • All Wi Fi devices fail: Restart the router.
  • Wi Fi fails, mobile data works: Router, ISP DNS, or local network issue.
  • Everything fails everywhere: The website may be down.

For an extra check, run nslookup example.com or dig example.com. If the answer looks wrong, DNS is likely involved. If DNS resolves fine, the issue may be HTTPS, firewall rules, hosting, or routing.

DNS TTL: the tiny timer behind the mess

DNS records have a timer called TTL. It means Time To Live. A TTL tells devices how long to keep a DNS answer.

A TTL might be 300 seconds. That is 5 minutes. It might be 3600 seconds. That is 1 hour. Some records stay cached longer, depending on the resolver and device behavior.

This is why DNS changes can feel weird. One person sees the new site. Another sees the old one. A third person gets an error and asks if the internet is broken. Classic.

Best troubleshooting order

Use this order when DNS acts up:

  1. Refresh the page. Simple, but worth trying.
  2. Try another browser. This catches browser cache issues.
  3. Flush local DNS. Fast and safe.
  4. Restart the device. Boring, but effective.
  5. Restart the router. Best for whole-home issues.
  6. Change DNS servers. Try Cloudflare 1.1.1.1 or Google 8.8.8.8.
  7. Contact the host or ISP. Do this after the easy fixes.
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Common mistakes to avoid

  • Do not reset the router first. A factory reset wipes settings. A restart does not.
  • Do not assume DNS is always the cause. Firewalls and expired certificates can look similar.
  • Do not test only one browser. Browser cache can trick you.
  • Do not forget VPN DNS. VPN apps often use their own DNS.
  • Do not panic after a domain change. TTL may still be counting down.

The simple rule

If one device has the problem, clear DNS on that device. If many devices have the problem, refresh the router. If the site fails on every network, the website or DNS provider may be the real culprit.

DNS sounds technical. It is really just saved directions. Sometimes the directions are old. Clear the local notes first. Then shake the router awake. Most of the time, that is enough to get the web behaving again.