How to Clear / Flush DNS Cache

So, you think you've got the filters set up correctly, but that website you expect to be blocked is STILL loading!  There are 2 options:

1. You don't really have your filters set up correctly, or
2. The filters are set up correctly, but you are trying to access a website that loaded successfully before the filters were set up (OR before you made a change in your block/allow settings).  That means that your browser, operating system, or router has "cached" the IP address for where the website actually lives.  You need to "flush your DNS cache", so that your browser, operating system, router makes the DNS query afresh  (i.e. so the website will be blocked properly).

When you implement DNS internet filters, you might need to flush the DNS cache for the following reasons:

1. Cache Persistence: The DNS cache stores IP addresses for domain names that your system has recently accessed. If you apply a new DNS filter, your system might still reference outdated IP addresses from the cache rather than using the new filtering rules. Flushing the DNS cache forces your system (browser, operating system, or router) to discard the old, cached IP addresses, ensuring that it queries the DNS server again under the new filter settings.

2. Avoiding Access to Blocked Content: If a DNS filter is set up to block specific websites, but the IP addresses of those sites are already cached, your system might still access those sites without querying the DNS server. Flushing the cache ensures that the system cannot access blocked sites using cached IP addresses, enforcing the filter effectively.

3. Propagation of DNS Changes: When DNS changes occur, such as switching to a DNS filter with updated rules, flushing the DNS cache ensures that your system quickly recognizes and adopts these changes. Without flushing, the system might continue to rely on outdated cache entries, leading to inconsistencies in access control.

4. Resolving Connectivity Issues: Sometimes, after setting up a DNS filter, you might encounter issues accessing websites or services. Flushing the DNS cache can resolve these connectivity problems by removing any potentially corrupted or stale cache entries that could interfere with the new DNS configurations.
   
   

Flushing the DNS cache is a simple way to ensure that your DNS filter settings are immediately and fully effective across your network or device.

1. Chrome
2. Safari
3. Edge
4. Firefox

1. Windows
2. Mac

If flushing the DNS in a specific browser and your Operating System do not seem to work, it is possible that your router itself is maintaining its own DNS cache.  Try unplugging the power cord for 60 seconds, and plugging it back in.  Oftentimes, this will flush the DNS cache.  

Alternatively, search for "how to flush DNS cached ROUTER BRAND + ROUTER MODEL.