diff --git a/p4app/controller.py b/p4app/controller.py
index d278129..f5873fa 100644
--- a/p4app/controller.py
+++ b/p4app/controller.py
@@ -13,9 +13,11 @@ import re
 
 import logging
 import argparse
-import ipaddress
 import subprocess
 
+# Broken in python2
+#import ipaddress
+
 
 logging.basicConfig()
 log = logging.getLogger("main")
@@ -26,20 +28,39 @@ class L2Controller(object):
         self.modes = ['base']
 
         # Network / egress
+        self.v6_mask = "/64"
+
         self.v6_routes = {}
         self.v6_routes[None] = []
         self.v6_routes['base'] = []
-        self.v6_routes['base'].append({ "net": "2001:db8:61::/64", "port": "1"})
-        self.v6_routes['base'].append({ "net": "2001:db8:62::/64", "port": "2"})
+        self.v6_routes['base'].append({ "net": "2001:db8:61::", "port": "1"})
+        self.v6_routes['base'].append({ "net": "2001:db8:62::", "port": "2"})
 
+        self.v4_mask = "/24"
         self.v4_routes = {}
         self.v4_routes[None] = []
         self.v4_routes['base'] = []
-        self.v4_routes['base'].append({ "net": "10.0.41.0/24", "port": "3"})
-        self.v4_routes['base'].append({ "net": "10.0.42.0/24", "port": "4"})
+        self.v4_routes['base'].append({ "net": "10.0.41.", "port": "3"})
+        self.v4_routes['base'].append({ "net": "10.0.42.", "port": "4"})
 
         self.init_boilerplate(sw_name)
 
+    @staticmethod
+    def prefix_to_net(net, mask):
+        """ work around ipaddress bug """
+        return "{}0/{}".format(net, mask)
+
+    @staticmethod
+    def prefix_to_host(net, mask):
+        """ work around ipaddress bug """
+        return "{}1/{}".format(net, mask)
+
+    def add_host_ips(host, net, ipaddr, dev):
+        subprocess.run(["mx", host, "ip", "addr", "flush", "dev", dev])
+        subprocess.run(["mx", host, "sysctl", "net.ipv6.conf.lo.disable_ipv6=0"])
+        subprocess.run(["mx", host, "sysctl", "net.ipv6.conf.{}.disable_ipv6=0".format(dev)])
+        subprocess.run(["mx", host, "ip", "addr", "add", ipaddr, "dev", dev])
+
     def init_boilerplate(self, sw_name):
         self.topo = Topology(db="topology.db")
         self.sw_name = sw_name
@@ -59,10 +80,12 @@ class L2Controller(object):
     def fill_tables(self):
         self.controller.table_clear("v6_routing")
         for v6route in self.v6_routes[self.mode]:
-            self.controller.table_add("v6_routing", "set_egress_port", [v6route['net']], [v6route['port']])
+            net = self.prefix_to_net(v6route['net'], self.v6_mask)
+            self.controller.table_add("v6_routing", "set_egress_port", [net], [v6route['port']])
 
         self.controller.table_clear("v4_routing")
         for v4route in self.v4_routes[self.mode]:
+            net = self.prefix_to_net(v4route['net'], self.v4_mask)
             self.controller.table_add("v4_routing", "set_egress_port", [v4route['net']], [v4route['port']])
 
     def config_hosts(self):
@@ -74,13 +97,12 @@ class L2Controller(object):
         for v6route in self.v6_routes[self.mode]:
             host   = "h{}".format(v6route['port'])
             dev    = "{}-eth0".format(host)
-            net    = ipaddress.ip_network(v6route['net'])
-            ipaddr = "{}/{}".format(net[1],net.prefix_length)
+            #net    = ipaddress.ip_network(v6route['net'])
+            #ipaddr = "{}/{}".format(net[1],net.prefix_length)
+            net    = self.prefix_to_net(v6route['net'], self.v6_mask)
+            ipaddr = self.prefix_to_host(v6route['net'], self.v6_mask)
 
-            subprocess.run(["mx", host, "ip", "addr", "flush", "dev", dev])
-            subprocess.run(["mx", host, "sysctl", "net.ipv6.conf.lo.disable_ipv6=0"])
-            subprocess.run(["mx", host, "sysctl", "net.ipv6.conf.{}.disable_ipv6=0".format(dev)])
-            subprocess.run(["mx", host, "ip", "addr", "add", ipaddr, "dev", dev])
+            self.add_host_ips(host, net, ipaddr, dev)
 
             # mx h$i "ip -6 route add default via 2001:db8:6::42"