Top Level Domains (TLDs) can be blocked using the Local Rules feature of Crystal Eye’s Content Filter application.
The Banned Sites feature of the content filter app is a powerful feature that can be used to to restrict access to specific TLDs such as .cm, .net, .org, etc
For instance, if you want to block a Chinese top level domain website that ends with a .cn then you may perform the following steps:
Step 1: Go to Security Configuration > Content Filter.
Step 2: Click the Policy Management tab.
Step 3: Click the Configure Policy button.
Note: In this instance we will edit or make changes to the default policy.
Step 4: Click the Edit button next to Banned Sites.
Step 5: You will now see the Banned Sites page. Click the Add button.
Step 6: Enter the Top Level Domain .cn in the textbox and click the Add button.