- Navigate to Network>DHCP Server
- Click the configure pencil icon to the right of the DHCP scope that you wish to enable option 66 for.
- Under the "advanced" tab navigate to the DHCP Generic Options drop down at the bottom select create new dhcp option object.
- Build a rule as seen below. Remember to ensure you use the provisioning server address of the server cluster you are on. If you have branded FQDNs you can also use that here.
- Once saved ensure the dchp option group is set to "Phones" and save.