The following article explains how to configure Isolated Zone
Deployment Steps
How it works:
Users will only be able to access Internet with the help of isolated zones and will not have access to other interfaces(eg: X0 subnet)
This release includes significant user interface changes and many new features that are different from the SonicOS 6.5 and earlier firmware. The below resolution is for customers using SonicOS 7.X firmware.

3. In Zones | Zone Settings disable the options as shown below
4. You can select security type as per you needs

5. Navigate to Network | Interfaces, Configure the interface
6. Select the Zone as Isolated Zone
7. Set the Mode/IP Assignment to Static IP Mode
8. Set an IP address for the network. (This will be the gateway IP for the network)
9. Comment and enable the management on the sub-interface if required and click OK

Further access can be enabled/restricted using access rules from Isolated Zone to WAN Zone
Please refer KB How to Configure Access Rules | SonicWall
This release includes significant user interface changes and many new features that are different from the SonicOS 6.2 and earlier firmware. The below resolution is for customers using SonicOS 6.5 firmware.

3. In Zones | Zone Settings disable the options as shown below
4. You can select security type as per you needs

5. Navigate to Manage | Network | Interfaces, Configure the interface
6. Select the Zone as Isolated Zone
7. Set the Mode/IP Assignment to Static IP Mode
8. Set an IP address for the network. (This will be the gateway IP for the network)
9. Comment and enable the management on the sub-interface if required and click OK

Further access can be enabled/restricted using access rules from Isolated Zone to WAN Zone
Please refer KB How to Configure Access Rules | SonicWall