firewall: repair the Vlan's get_new_address() method. Issue: #425

circle/firewall/models.py

@@ -36,6 +36,7 @@ from django.core.validators import MinValueValidator, MaxValueValidator
 from django.core.urlresolvers import reverse
 import django.conf
 from django.db.models.signals import post_save, post_delete
+from django.db.models import Q
 from celery.exceptions import TimeoutError
 from netaddr import IPSet, EUI, IPNetwork, IPAddress, ipv6_full
 
@@ -499,7 +500,12 @@ class Vlan(AclBase, models.Model):
 
     def get_new_address(self):
         hosts = self.host_set
-        used_v4 = IPSet(hosts.values_list('ipv4', flat=True))
+        query = Q(shared_ip=False)\
+            | Q(external_ipv4__isnull=False)\
+            | Q(vlan=self)
+        ipv4_hosts = Host.objects.filter(query)
+
+        used_v4 = IPSet(ipv4_hosts.values_list('ipv4', flat=True))
         used_v6 = IPSet(hosts.exclude(ipv6__isnull=True)
                         .values_list('ipv6', flat=True))