Why Can’t I See My Website? Is It an ISP Issue?

Sometimes when you can’t access a website, it may be due to DNS caching issues rather than your ISP directly. DNS clients (like your computer or router) store the results of domain name lookups to speed up browsing. But if a bad or outdated DNS record is cached, it can prevent your browser from finding the site.

What Is DNS Cache?

DNS cache stores the IP addresses of websites you’ve visited recently. If the cache holds wrong information, you might see errors or be unable to visit certain sites until the cache updates or is cleared.

How to Fix This: Flush Your DNS Cache

Flushing the DNS cache forces your system to discard stored DNS records and fetch fresh information from DNS servers.

How to Flush DNS Cache on Windows

1. Open Command Prompt (type cmd in Start menu and run as administrator).

2. Run this command:

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   ipconfig /flushdns

3. You should see:

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   Windows IP Configuration Successfully flushed the DNS Resolver Cache.

4. Optional: To view current DNS cache entries, use:

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   ipconfig /displaydns

Disable DNS Caching on Windows (Temporary)

If you want to temporarily stop DNS caching (until reboot), run:

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net stop dnscache

or

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sc servername stop dnscache

To permanently disable, change the DNS Client service startup type to Disabled via Services tool.

Adjust DNS Cache Settings on Windows

You can fine-tune DNS cache time-to-live (TTL) via Windows Registry:

• MaxCacheTtl = max time DNS results are cached (default: 86400 seconds / 24 hours).

• MaxNegativeCacheTtl = max time failed lookups are cached (default: 900 seconds / 15 minutes).

Set these values in:

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HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Dnscache\Parameters

How to Flush DNS Cache on macOS

• On macOS Leopard and newer:

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  sudo dscacheutil -flushcache

• On macOS 10.5.1 and older:

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  sudo lookupd -flushcache

How to Flush DNS Cache on Linux

Most Linux systems use the nscd daemon for DNS caching.

Restart nscd to flush DNS cache:

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sudo /etc/init.d/nscd restart

Summary

If you can’t see your website, try flushing your DNS cache first. This often solves DNS-related issues without needing to contact your ISP. If problems persist after flushing DNS, then it might be worth checking with your ISP or hosting provider.