The screenshot provided above works is for Web control policy which looks the same for servers and for endpoints. The difference is that Web control for endpoints is a User-based policy only - you cannot make it device-specific, but Server web control policy is only device-specific. Web control is not designed to block everything but to limit what can be accessed for that one machine.
As a workaround, you can create a new Web control policy, assign it to the desired server, confirm that the policy is enforced. Populate a list of resources in Global settings -> Website management with a tag, then as Sophos User930 mentioned block all categories and allow everything tagged. If this for some reason doesn't fit your requirements, then your best bet is to set up access through web appliance\firewall.
The screenshot provided above works is for Web control policy which looks the same for servers and for endpoints. The difference is that Web control for endpoints is a User-based policy only - you cannot make it device-specific, but Server web control policy is only device-specific. Web control is not designed to block everything but to limit what can be accessed for that one machine.
As a workaround, you can create a new Web control policy, assign it to the desired server, confirm that the policy is enforced. Populate a list of resources in Global settings -> Website management with a tag, then as Sophos User930 mentioned block all categories and allow everything tagged. If this for some reason doesn't fit your requirements, then your best bet is to set up access through web appliance\firewall.
