https://bugs.launchpad.net/neutron/+bug/1596075

neutron-overlap.py

import sys
from neutronclient.v2_0 import client
neutron = client.Client(username='don',
                        password='XXX',
                        tenant_name='don',auth_url='https://keystone.sandvine.rocks/v2.0')

ids = []
sids = []
for i in range(1,254):
    network = {'name': 'pnet-%s' % i, 'admin_state_up': True}

    n = neutron.create_network({'network':network})
    id = n['network']['id']
    ids.append(id)
    srange="172.17.%u.9" % i
    erange="172.17.%u.254" % i
    cidr="172.17.%u.0/24" % i
    name = "subnet-%u" % i
    subnet = {'enable_dhcp': True, 
              'network_id': id, 
              'allocation_pools': [{'start': srange, 'end': erange}],
              'ip_version': 4,
              'cidr': cidr,
              'name': name} 
    s = neutron.create_subnet({'subnet':subnet})
    sid = s['subnet']['id']
    sids.append(sid)

for i in sids:
    neutron.delete_subnet({'subnet':{'id': i}})

for i in ids:
    neutron.delete_network({'network':{'id': i}})