diff --git a/p4app/controller.py b/p4app/controller.py
index d46dfa0..413f362 100644
--- a/p4app/controller.py
+++ b/p4app/controller.py
@@ -110,16 +110,16 @@ class L2Controller(object):
         for mode in self.modes:
             self.nat64_map[mode] = []
 
-        # specific settings
+        # specific settings -- only need the address (=offset), no mask
         for mode in ["range_router"]:
             for net in self.v6_routes[mode]:
-                v6_net = net['net']I'
-                v4_net = self.info['v4_nat64_map'].next()
+                v6_net = net['net'].network_address
+                v4_net = self.info['v4_nat64_map'].next().network_address
 
                 self.nat64_map[mode].append({
                     "v6_network": v6_net,
                     "v4_network": v4_net,
-                    "nat64_prefix": self.info['nat64_prefix']
+                    "nat64_prefix": self.info['nat64_prefix'].network_address
                 })
 
         self.init_boilerplate(sw_name)