[DevStack] ERROR: Duplicate names {'internal_net2'}

Hi all,
Im trying to deploy stack with 3 VMs and 1 VN/Subnet.
My problem is that when I deploy it over following HOT package/template it complains:
Code:stack@vlab:~$ openstack stack create -t HOT_test_net.yaml HOT_test_net
ERROR: Duplicate names {'internal_net2'}Then, when I remove following part:
Code: internal_net2:
type: string
default: "InternalNetwork"Then I get this error but as far as I can say VM-3_port1 does have internal_net2 provided/assigned.
Code:stack@vlab:~$ openstack stack create -t HOT_test_net.yaml HOT_test_net
ERROR: Property error: : resources.VM-3_port1.properties.network: : The Parameter (internal_net2) was not provided.Can anyone help here, please?

Code:heat_template_version: 2014-10-16

description: HOT template for ECM instance

parameters:
VM_flavor:
type: string
default: "rr1.small"

VM_image:
type: string
default: "cirros-0.4.0-x86_64-disk"

VM_availability_zone:
type: string
default: "RX-1"

VM_nodename1:
type: string
default: "VM_1"

VM_nodename2:
type: string
default: "VM_2"

VM_nodename3:
type: string
default: "VM_3"

internal_net2:
type: string
default: "InternalNetwork"
VM_node1_IP_int:
type: string
default: "192.168.50.6"

VM_node2_IP_int:
type: string
default: "192.168.50.7"

VM_node3_IP_int:
type: string
default: "192.168.50.8"

resources:
internal_net2:
type: OS::Neutron::Net
properties:
admin_state_up: true
name: internal_net2
internal_net2_subnet:
type: OS::Neutron::Subnet
properties:
network: { get_resource: internal_net2 }
cidr: "192.168.50.0/24"
dns_nameservers: ["8.8.8.8"]
gateway_ip: "192.168.50.1"
ip_version: 4
VM-1_port1:
type: OS::Neutron::Port
properties:
name: Port_VM-1
network: { get_param: internal_net2 }
fixed_ips:
- ip_address: { get_param: VM_node1_IP_int }

VM-2_port1:
type: OS::Neutron::Port
properties:
name: Port_VM-2
network: { get_param: internal_net2 }
fixed_ips:
- ip_address: { get_param: VM_node2_IP_int }

VM-3_port1:
type: OS::Neutron::Port
properties:
name: Port_VM-3
network: { get_param: internal_net2 }
fixed_ips:
- ip_address: { get_param: VM_node3_IP_int }

VM-1:
type: OS::Nova::Server
properties:
config_drive: "true"
name: { get_param: VM_nodename1 }
flavor: { get_param: VM_flavor }
image: { get_param: VM_image }
availability_zone: { get_param: VM_availability_zone }
networks:
- port: { get_resource: VM-1_port1 }

VM-2:
type: OS::Nova::Server
properties:
config_drive: "true"
name: { get_param: VM_nodename2 }
flavor: { get_param: VM_flavor }
image: { get_param: VM_image }
availability_zone: { get_param: VM_availability_zone }
networks:
- port: { get_resource: VM-2_port1 }

VM-3:
type: OS::Nova::Server
properties:
config_drive: "true"
name: { get_param: VM_nodename3 }
flavor: { get_param: VM_flavor }
image: { get_param: VM_image }
availability_zone: { get_param: VM_availability_zone }
networks:
- port: { get_resource: VM-3_port1 }