diff -Nru isc-dhcp-4.3.3/debian/changelog isc-dhcp-4.3.3/debian/changelog
--- isc-dhcp-4.3.3/debian/changelog	2016-12-09 12:45:11.000000000 -0500
+++ isc-dhcp-4.3.3/debian/changelog	2017-02-01 08:44:27.000000000 -0500
@@ -1,3 +1,15 @@
+isc-dhcp (4.3.3-5ubuntu12.7) xenial; urgency=medium
+
+  * debian/control : Add "Replaces:" flag for binary package isc-dhcp-client to allow the 
+    packaging system to resolve which package should be removed "isc-dhcp-client-nodds" 
+    and which one should be installed "isc-dhcp-client" during a release upgrade from Trusty
+    to Xenial. This modification is necessary to ensure a successfull release upgrade if user  
+    in Trusty uses package isc-dhcp-client-noddns.
+
+    Note that this doesn't change the behavior if Trusty uses has isc-dhcp-client installed.
+
+ -- Eric Desrochers <eric.desrochers@canonical.com>  Wed, 01 Feb 2017 08:36:18 -0500
+
 isc-dhcp (4.3.3-5ubuntu12.6) xenial; urgency=medium
 
   * debian/initramfs/lib/etc/dhcp/dhclient-enter-hooks.d/config: clean up
diff -Nru isc-dhcp-4.3.3/debian/control isc-dhcp-4.3.3/debian/control
--- isc-dhcp-4.3.3/debian/control	2016-12-09 12:45:11.000000000 -0500
+++ isc-dhcp-4.3.3/debian/control	2017-02-01 08:35:19.000000000 -0500
@@ -127,6 +127,8 @@
  iproute2 [linux-any] | freebsd-net-tools [kfreebsd-any],
 Recommends:
  isc-dhcp-common,
+Replaces:
+ isc-dhcp-client-noddns (<< 4.2.4-7ubuntu12.9),
 Suggests:
  resolvconf,
  avahi-autoipd,