diff --git a/p4app/controller.py b/p4app/controller.py
index 7984f29..ab78600 100644
--- a/p4app/controller.py
+++ b/p4app/controller.py
@@ -171,7 +171,7 @@ class L2Controller(object):
             host   = "h{}".format(v6route['port'])
             dev    = "{}-eth0".format(host)
             net    = v6route['net']
-            ipaddr = "{}/{}".format(net[1],net.prefix_len)
+            ipaddr = "{}/{}".format(net[1],net.prefixlen)
 
             self.add_host_ips(host, str(net), str(ipaddr), dev)