diff -Nru isc-dhcp-4.3.3/debian/changelog isc-dhcp-4.3.3/debian/changelog
--- isc-dhcp-4.3.3/debian/changelog	2016-10-20 16:55:33.000000000 +0000
+++ isc-dhcp-4.3.3/debian/changelog	2016-10-21 16:46:20.000000000 +0000
@@ -1,3 +1,13 @@
+isc-dhcp (4.3.3-5ubuntu17) zesty; urgency=medium
+
+  * debian/initramfs/lib/etc/dhcp/dhclient-enter-hooks.d/config: fix script to
+    not write to /run/net-$iface.conf when dealing with IPv6; which should only
+    write to a /run/net6-$iface.conf file.
+  * debian/README.Debian: document what this config script is and why a hook is
+    shipped for the initramfs.
+
+ -- Mathieu Trudel-Lapierre <cyphermox@ubuntu.com>  Fri, 21 Oct 2016 12:46:20 -0400
+
 isc-dhcp (4.3.3-5ubuntu16) zesty; urgency=medium
 
   * ipv6: wait for duplicate address detection to finish (LP: #1633479).
diff -Nru isc-dhcp-4.3.3/debian/initramfs-tools/lib/etc/dhcp/dhclient-enter-hooks.d/config isc-dhcp-4.3.3/debian/initramfs-tools/lib/etc/dhcp/dhclient-enter-hooks.d/config
--- isc-dhcp-4.3.3/debian/initramfs-tools/lib/etc/dhcp/dhclient-enter-hooks.d/config	2016-10-20 16:55:33.000000000 +0000
+++ isc-dhcp-4.3.3/debian/initramfs-tools/lib/etc/dhcp/dhclient-enter-hooks.d/config	2016-10-21 16:46:20.000000000 +0000
@@ -1,9 +1,13 @@
 #!/bin/sh
 
-echo "DEVICE=$interface" >> /run/net-$interface.conf
+IPVER=""
+if echo "$reason" | grep -q '6$'; then
+	IPVER=6
+fi
 
 case "$reason" in
 BOUND)
+	echo "DEVICE=$interface" >> /run/net-$interface.conf
 	echo "PROTO=dhcp" >> /run/net-$interface.conf
 	echo "IPV4PROTO=dhcp" >> /run/net-$interface.conf
 	echo "IPV4ADDR=$new_ip_address" >> /run/net-$interface.conf
@@ -12,27 +16,27 @@
 	echo "IPV4GATEWAY=$new_routers" >> /run/net-$interface.conf
 	echo "IPV4DNS0=$new_domain_name_servers" >> /run/net-$interface.conf
 	echo "ROOTSERVER=$new_routers" >> /run/net-$interface.conf
+	if [ -n "$host_name"]; then
+		echo "HOSTNAME=$new_host_name" >> /run/net-$interface.conf
+	fi
+	if [ -n "$domain_name"]; then
+		echo "DNSDOMAIN=$new_domain_name" >> /run/net-$interface.conf
+	fi
 	if [ -n "$new_domain_search"]; then
 		echo "DOMAINSEARCH=$new_domain_search" >> /run/net-$interface.conf
 	fi
 	;;
 BOUND6)
-	echo "IPV6PROTO=dhcp6" >> /run/net-$interface.conf
-	echo "IPV6ADDR=$new_ip6_address" >> /run/net-$interface.conf
-	echo "IPV6NETMASK=$new_ip6_prefixlen" >> /run/net-$interface.conf
-	echo "IPV6DNS0=$new_dhcp6_name_servers" >> /run/net-$interface.conf
+	echo "IPV6PROTO=dhcp6" >> /run/net6-$interface.conf
+	echo "IPV6ADDR=$new_ip6_address" >> /run/net6-$interface.conf
+	echo "IPV6NETMASK=$new_ip6_prefixlen" >> /run/net6-$interface.conf
+	echo "IPV6DNS0=$new_dhcp6_name_servers" >> /run/net6-$interface.conf
 	if [ -n "$new_dhcp6_domain_search"]; then
-		echo "IPV6DOMAINSEARCH=$new_dhcp6_domain_search" >> /run/net-$interface.conf
+		echo "IPV6DOMAINSEARCH=$new_dhcp6_domain_search" >> /run/net6-$interface.conf
 	fi
 	;;
 esac
 
-if [ -n "$host_name"]; then
-	echo "HOSTNAME=$new_host_name" >> /run/net-$interface.conf
-fi
-if [ -n "$domain_name"]; then
-	echo "DNSDOMAIN=$new_domain_name" >> /run/net-$interface.conf
-fi
 
 for prefix in '' 'cur_' 'new_' 'old_'; do
 	# loop over the DHCP variables passed to dhclient-script
@@ -50,7 +54,7 @@
 
 		# show only variables with values set
 		if [ -n "${content}" ]; then
-			echo "$var='${content}'" >> /run/net-$interface.conf
+			echo "$var='${content}'" >> /run/net$IPVER-$interface.conf
 		fi
 	done
 done
diff -Nru isc-dhcp-4.3.3/debian/README.Debian isc-dhcp-4.3.3/debian/README.Debian
--- isc-dhcp-4.3.3/debian/README.Debian	2016-10-20 16:55:33.000000000 +0000
+++ isc-dhcp-4.3.3/debian/README.Debian	2016-10-21 16:46:20.000000000 +0000
@@ -34,3 +34,24 @@
 profile. Please see https://wiki.ubuntu.com/DebuggingApparmor before filing a
 bug against this software.
 
+
+initramfs-tools hook and supplementary files
+--------------------------------------------
+
+isc-dhcp-client ships a hook for initramfs-tools to install dhclient in the
+initramfs, so that systems may bring up IPv4 and IPv6 networking in early
+userspace, in order to mount remote filesystems, etc.
+
+The included "config" script for dhclient-enter-hooks shipping in isc-dhcp-
+client for the initramfs is based off the existing "debug" script.
+
+It writes out /run/net-$iface.conf and /run/net6-$iface.conf in a format that
+is compatible with the old ipconfig format, along with new variables in the
+same idea for IPv6 (which was not supported by ipconfig).
+
+For future use, all the environment variables available to dhclient hooks are
+also dumped to the file, so they may be used if the compatibility ones are not
+sufficient.
+
+See http://git.kernel.org/cgit/libs/klibc/klibc.git/tree/usr/kinit/ipconfig/README.ipconfig
+