This tutorial will explain How can to delete negative DNS cache information from the bluecoat ProxySG device
To delete a DNS entry:
1. Go to Statistics->Advanced->DNS on the ProxySG Management Console.
2. Click Delete a DNS Entry and on the address bar of the web browser, append the hostname to the end of the URL. For example, if you would like to delete unexpected negative dns cache entry for foo.bar.com, enter:
If you would like to verify the DNS cache entry information, click Show information on a DNS entry and append the hostname to the end of the URL. For example: