Without a network node of some kind, you will not have a dhcp service assigning IPs. You may want to check with your hardware vendor to see if there is a neutron plugin that allows for a neutron node to run (providing openflow and dhcp) while the hardware would take care of the rest.

As jdexter said, openstack deployment involves a network component. Now, in your case as you are saying you do not have neutron network - you could as well be having nova-network which is a Flat network. With Flat network you could use FlatDHCPManager which can assign an IP address to the VMs. Can you please check and tell if you are using nova-network, as you said you are not using neutron? And if yes, check whether FlatDHCPManager is being used/configured or not. Solution to your problem depends on what scenario it is - is it that there is no dhcp configured or is it problem with communication of instances with the dhcp.