On Fri, 17 Jan 2020, Leonardo Boselli wrote:
subnet 10.240.13.0 netmask 255.255.255.0 { }
including not an empty declaration but a full declaration (just without range) did work .
-- Leonardo Boselli Dipartimento Ingegneria Civile e Ambientale UNIFI tel +39 0552758808 +39 3488605348