Flush DNS

Flush DNS

The DNS (Domain Name System) is the backbone of how we navigate the internet. Every time you type a website address into your browser, the DNS system translates that human-readable domain name into a numerical IP address that computers use to communicate. Your operating system caches these lookups locally to speed up future visits, but sometimes this cache becomes outdated or corrupted.

When DNS cache entries go stale, you may experience problems such as being unable to reach a website or being directed to an old server. The solution is to flush your DNS cache, which forces your computer to request fresh DNS information from the network.

How to Flush DNS Cache in Windows

Flushing the DNS cache in Windows is straightforward using the ipconfig /flushdns command. Follow these steps:

1. Click the Start menu.
2. Type cmd in the search box.
3. Right-click on Command Prompt and select Run as administrator.
4. Type ipconfig /flushdns in the command window.
5. Press Enter. You should see a confirmation message: "Successfully flushed the DNS Resolver Cache."

Understanding the DNS System

The DNS system is distributed across thousands of servers worldwide. When you visit a website, your request may pass through several DNS servers before the correct IP address is returned. To reduce the load on these servers and speed up browsing, your operating system stores (caches) DNS responses locally.

Each DNS record has a TTL (Time to Live) value that controls how long the record should be cached before it expires. Normally, this is set to 24 hours (86400 seconds), but it can vary depending on the domain configuration. Once the TTL expires, the cached entry is discarded and a fresh lookup is performed on the next request.

How to Check If You Need to Flush DNS

If you suspect a DNS issue, you can verify it by pinging your domain from the command prompt. Open a command window and type:

ping yourdomain.com

If the IP address returned is wrong and you know your DNS settings are correct, it is time to flush your DNS cache. After flushing, ping the domain again to confirm the correct IP address is now being resolved.