Fixed typo error

Change-Id: I585ce7d8c15ec2151d496e079ae1b9d5784734da
diff --git a/trellis/trellis_hag.py b/trellis/trellis_hag.py
index 5073e23..33ceede 100755
--- a/trellis/trellis_hag.py
+++ b/trellis/trellis_hag.py
@@ -9,7 +9,7 @@
 from mininet.link import TCLink
 from ipaddress import ip_network
 from routinglib import BgpRouter
-from routinglib import RoutedHost, RoutedHost6, NAT
+from routinglib import RoutedHost, RoutedHost6, UserNAT
 from trellislib import DhcpClient, Dhcp6Client, Dhcp4and6Client, DhcpRelay, DhcpServer, Dhcp6Server
 from trellislib import DualHomedDhcpClient
 from trellislib import DualHomedDhcp4and6Client