Clear Cache

Policy changes on the DNS Firewall web application are propogated almost immediately to all networks and roaming clients for an account.

However, DNS record information is usually cached (stored on your local browser, computer, or network forwarder) for a specific amount of time; anywhere from 5 minutes to 8 hours is normal.

Policy Changes

Allowing Domains

When adding domains to a policy’s Allow list, or deselecting categories from being blocked, you can expect to see the changes reflected in your network/computers within a minute.

Blocking Domains and Changing Policies

When adding domains to a policy’s Block list, selecting additional categories to be blocked, or assigning a different policy to a network. Domains may have been visited recently on computers on your network, and hence the cache time (TTL) as set by the domain’s DNS administrators, could take minutes or hours to expire.

How to Clear Your Cache

If you are encountering issues with content filtering, allow, block or internal domains not working as expected, please follow the instructions below to clear your cache:

Browser Cache

Mozilla Firefox

• Type about:config in Firefox’s address bar and acknowledge the warning that appears
• In the General menu, scroll down to Network Settings.
• 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)
• Now go back and change the value to 3600

Google Chrome

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

Safari

Nothing specific to be done here.

Operating System Cache

Windows 7 and Later:

• Press ⊞ Win + X
• Right-click Command Prompt and select Run as Administrator.
• Run the following command and hit enter:

   ipconfig /flushdns

Mac OSX 10.9 and Later

• Launch the Terminal application
• Run the following command and hit enter:

   sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

Mac OSX 10.8 and Earlier

• Launch Terminal (under Applications/Utilities)
• Run the following command and hit enter:

   sudo killall -HUP mDNSResponder

Linux (Ubuntu)

• Open a terminal window.
• Run the following command and hit enter:

   sudo service network-manager restart