Here is what I am using:
# Add DHCP custom range for VLAN 4 being a private network
#
interface=vlan4
dhcp-range=vlan4,10.10.11.10,10.10.11.250,24h
dhcp-option=vlan4,15,NULEAFGUEST
dhcp-option=vlan4,3,10.10.11.1
dhcp-option=vlan4,6,10.10.11.1,0.0.0.0
My LAN subnet is 10.10.10.1