Neutron network creation gets fail

Issue

• While creating the network gets below error

  root@packstack10 ~(keystone_admin)]# neutron net-create <network-name> --provider:network_type vlan provider:physical_network provider --router:external=True --shared
  neutron CLI is deprecated and will be removed in the future. Use openstack CLI instead.
  Invalid values_specs provider:physical_network provider --router:external=True
  

• Creating the second flat external networks gets fail with below error

  Unable to create the flat network. Physical network datacentre is in use.