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Use this article for steps to clear browser and system cache if updates to a Filtering Policy are not reflected in the network environment's behavior. 

Changes to policies in the dashboard apply across the DNSFilter server fleet instantaneously, so there are not delays to enforcing changes from the app's perspective.

The DNSFilter Block Page has a 30-second cache time (TTL), so when removing domains from the Block List or unblocking a Category there's no need to clear network or browser cache. 

However, when adding domains to the Block List or blocking a Category, recently visited domains' DNS could be cached locally. DNS record information is usually cached (stored on local browsers, computers, or network forwarders) for a specific amount of time; anywhere from 5 minutes to 8 hours is normal.

How to clear browser and system cache

If you are encountering issues with content filtering, such as blocking not working according to your policy, we ask that you first clear both your system cache and browser cache. Instructions to do this are below:

Browser Cache

Google Chrome (Windows and Mac):

1. In a new tab, type the following into the address bar and hit enter: chrome://net-internals/#dns
2. Click the button labeled “clear host cache”

Firefox:

1. Type about:config in Firefox’s address bar and acknowledge the warning that appears
2. Find an entry called network.dnsCacheExpiration and set its value to 0 (If there’s no such entry, create a new integer item with the name above and a value of 0)
3. Now go back and change the value to 3600

Safari (Windows and Mac):

Resetting the DNS Cache on Windows automatically flushes the DNS cache on Safari. Nothing to do here!

Edge

Go to Settings > Privacy > Clear browsing data and select Ctrl+Shift+Del. Or type "edge://settings/clearbrowserdata" in the address bar to access this function.

Operating System Cache

Windows 7 and Later:

1. Press ⊞ Win + X
2. Right-click Command Prompt and select Run as Administrator.
3. Run the following command and hit enter: ipconfig /flushdns

Mac OSX 10.9 and Later:

1. Launch the Terminal application
2. Run the following command and hit enter:
   sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

Mac OSX 10.8 and Earlier:

1. Launch Terminal (under Applications/Utilities)
2. Run the following command and hit enter: sudo killall -HUP mDNSResponder

Linux (Ubuntu)

1. Open a terminal window.
2. Run the following command and hit enter:
   sudo service network-manager restart