We want to create an IP Firewall rule in the IP Firewall policies to allow traffic only to an IP-RANGE. However it seems we only can configure a hostname or an IP-address, not an entire ip-range. Is this correct?
You should be able to create an IP range object, and then apply it to the IP firewall rules to block an entire range of IP addresses. This guide reviews how to do this. Is that what you were looking for?