Index: etc/defaults/rc.conf
===================================================================
--- etc/defaults/rc.conf
+++ etc/defaults/rc.conf
@@ -113,6 +113,9 @@
 #background_dhclient_fxp0="YES"	# Start dhcp client on fxp0 in the background.
 synchronous_dhclient="NO"	# Start dhclient directly on configured
 				# interfaces during startup.
+#dhclient6_program="/sbin/dhclient"	# Path to DHCPv6 client program.
+dhclient6_flags=""		# Extra flags to pass to DHCPv6 client.
+background_dhclient6="NO"	# Start DHCPv6 client in the background.
 defaultroute_delay="30"		# Time to wait for a default route on a DHCP interface.
 defaultroute_carrier_delay="5"	# Time to wait for carrier while waiting for a default route.
 netif_enable="YES"		# Set to YES to initialize network interfaces
Index: etc/network.subr
===================================================================
--- etc/network.subr
+++ etc/network.subr
@@ -234,6 +234,16 @@
 		_cfg=0
 	fi
 
+	if dhcp6if $1; then
+		if [ $_cfg -ne 0 ] ; then
+			${IFCONFIG_CMD} $1 up
+		fi
+		if syncdhcp6if $1; then
+			/etc/rc.d/dhclient6 start $1
+		fi
+		_cfg=0
+	fi
+
 	return $_cfg
 }
 
@@ -259,6 +269,11 @@
 		_cfg=0
 	fi
 
+	if dhcp6if $1; then
+		/etc/rc.d/dhclient6 stop $1
+		_cfg=0
+	fi
+
 	if ifexists $1; then
 		${IFCONFIG_CMD} $1 down
 		_cfg=0
@@ -325,9 +340,12 @@
 	for _arg in $_tmpargs; do
 		case $_arg:$_vnet in
 		[Dd][Hh][Cc][Pp]:0) ;;
+		[Dd][Hh][Cc][Pp]6:0) ;;
 		[Nn][Oo][Aa][Uu][Tt][Oo]:0) ;;
 		[Nn][Oo][Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp]:0) ;;
+		[Nn][Oo][Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp]6:0) ;;
 		[Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp]:0) ;;
+		[Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp]6:0) ;;
 		[Ww][Pp][Aa]:0) ;;
 		[Hh][Oo][Ss][Tt][Aa][Pp]:0) ;;
 		vnet:0)	_vnet=1 ;;
@@ -396,6 +414,43 @@
 	return 1
 }
 
+# dhcp6if if
+#	Returns 0 if the interface is a DHCP6 interface and 1 otherwise.
+dhcp6if()
+{
+	local _tmpargs _arg
+	_tmpargs=`_ifconfig_getargs $1 ipv6`
+
+	case $1 in
+	lo[0-9]*|\
+	stf[0-9]*|\
+	faith[0-9]*|\
+	lp[0-9]*|\
+	sl[0-9]*)
+		return 1
+		;;
+	esac
+	if noafif $1; then
+		return 1
+	fi
+
+	for _arg in $_tmpargs; do
+		case $_arg in
+		[Dd][Hh][Cc][Pp]6)
+			return 0
+			;;
+		[Nn][Oo][Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp]6)
+			return 0
+			;;
+		[Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp]6)
+			return 0
+			;;
+		esac
+	done
+
+	return 1
+}
+
 # syncdhcpif
 #	Returns 0 if the interface should be configured synchronously and
 #	1 otherwise.
@@ -422,6 +477,32 @@
 	checkyesno synchronous_dhclient
 }
 
+# syncdhcp6if
+#	Returns 0 if the interface should be configured synchronously and
+#	1 otherwise.
+syncdhcp6if()
+{
+	local _tmpargs _arg
+	_tmpargs=`_ifconfig_getargs $1 ipv6`
+
+	if noafif $1; then
+		return 1
+	fi
+
+	for _arg in $_tmpargs; do
+		case $_arg in
+		[Nn][Oo][Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp]6)
+			return 1
+			;;
+		[Ss][Yy][Nn][Cc][Dd][Hh][Cc][Pp]6)
+			return 0
+			;;
+		esac
+	done
+
+	checkyesno synchronous_dhclient6
+}
+
 # wpaif if
 #	Returns 0 if the interface is a WPA interface and 1 otherwise.
 wpaif()
@@ -1620,8 +1701,9 @@
 #	List all network interfaces. The type of interface returned
 #	can be controlled by the type argument. The type
 #	argument can be any of the following:
-#		nodhcp	- all interfaces, excluding DHCP configured interfaces
+#		nodhcp	- all interfaces, excluding DHCP/DHCP6 configured interfaces
 #		dhcp	- list only DHCP configured interfaces
+#		dhcp6	- list only DHCP6 configured interfaces
 #		noautoconf	- all interfaces, excluding IPv6 Stateless
 #				  Address Autoconf configured interfaces
 #		autoconf	- list only IPv6 Stateless Address Autoconf
@@ -1687,7 +1769,9 @@
 	nodhcp)
 		for _if in ${_tmplist} ; do
 			if ! dhcpif $_if && \
-			   [ -n "`_ifconfig_getargs $_if`" ]; then
+			   ! dhcp6if $_if && \
+			   ( [ -n "`_ifconfig_getargs $_if`" ] || \
+			     [ -n "`_ifconfig_getargs $_if ipv6`" ] ); then
 				_list="${_list# } ${_if}"
 			fi
 		done
@@ -1699,6 +1783,13 @@
 			fi
 		done
 	;;
+	dhcp6)
+		for _if in ${_tmplist} ; do
+			if dhcp6if $_if; then
+				_list="${_list# } ${_if}"
+			fi
+		done
+	;;
 	noautoconf)
 		for _if in ${_tmplist} ; do
 			if ! ipv6_autoconfif $_if && \
Index: etc/rc.d/dhclient6
===================================================================
--- /dev/null
+++ etc/rc.d/dhclient6
@@ -0,0 +1,75 @@
+#!/bin/sh
+#
+# $FreeBSD$
+#
+
+# PROVIDE: dhclient6
+# KEYWORD: nojail nostart
+
+. /etc/rc.subr
+. /etc/network.subr
+
+ifn="$2"
+
+name="dhclient6"
+rcvar=
+# ISC dhcp-client from ports (the only dhcp-client tested with this script so
+# far) doesn't use a per-interface pidfile.
+#pidfile="/var/run/${name}.${ifn}.pid"
+pidfile="/var/run/${name}.pid"
+start_precmd="dhclient6_prestart"
+stop_precmd="dhclient6_pre_check"
+
+# rc_force check can only be done at the run_rc_command
+# time, so we're testing it in the pre* hooks.
+dhclient6_pre_check()
+{
+	if [ -z "${rc_force}" ] && ! dhcp6if $ifn; then
+		local msg
+		msg="'$ifn' is not a DHCP6-enabled interface"
+		if [ -z "${rc_quiet}" ]; then
+			echo "$msg"
+		else
+			debug "$msg"
+		fi
+			exit 1
+	fi
+}
+
+dhclient6_prestart()
+{
+	dhclient6_pre_check
+
+	# Interface-specific flags (see rc.subr for $flags setting)
+	specific=$(get_if_var $ifn dhclient6_flags_IF)
+	if [ -z "$flags" -a -n "$specific" ]; then
+		rc_flags=$specific
+	fi
+
+	background_dhclient6=$(get_if_var $ifn background_dhclient6_IF $background_dhclient6)
+	if checkyesno background_dhclient6; then
+		rc_flags="${rc_flags} -b"
+	fi
+
+	rc_flags="${rc_flags} ${ifn}"
+
+	# Wait for DAD to complete on the link local address. If DAD isn't
+	# complete, then dhclient won't be able to bind and will exit.
+	while ifconfig ${ifn} | grep "inet6.*%${ifn}" | grep -q tentative
+	do
+	    sleep 1
+	done
+	
+}
+
+load_rc_config $name
+load_rc_config network
+
+if [ -z $ifn ] ; then
+	# only complain if a command was specified but no interface
+	if [ -n "$1" ] ; then
+		err 1 "$0: no interface specified"
+	fi
+fi
+
+run_rc_command "$1"
Index: sbin/dhclient/dhclient-script
===================================================================
--- sbin/dhclient/dhclient-script
+++ sbin/dhclient/dhclient-script
@@ -22,6 +22,7 @@
 ARP=/usr/sbin/arp
 HOSTNAME=/bin/hostname
 IFCONFIG='/sbin/ifconfig -n'
+RESOLVCONF='/sbin/resolvconf'
 
 LOCALHOST=127.0.0.1
 
@@ -35,6 +36,19 @@
 # Helper functions that implement common actions.
 #
 
+resolvconf_enabled() {
+	case "$resolvconf_enable" in
+	# "no", "false", "off", or "0"
+	[Nn][Oo]|[Ff][Aa][Ll][Ss][Ee]|[Oo][Ff][Ff]|0)
+		return 1
+		;;
+
+	*)
+		return 0
+		;;
+	esac
+}
+
 check_hostname() {
 	current_hostname=`$HOSTNAME`
 	if [ -z "$current_hostname" ]; then
@@ -57,6 +71,10 @@
 	eval "$IFCONFIG $interface inet -alias $old_ip_address $medium"
 }
 
+delete_old_address6() {
+	eval "$IFCONFIG $interface inet6 ${old_ip6_address}/${old_ip6_prefixlen} -alias"
+}
+
 add_new_address() {
 	eval "$IFCONFIG $interface \
 		inet $new_ip_address \
@@ -70,6 +88,18 @@
 	$LOGGER "New Routers ($interface): $new_routers"
 }
 
+add_new_address6() {
+	if [ -z ${new_ip6_address} ] || [ -z ${new_ip6_prefixlen} ] ; then
+		exit_with_hooks 2;
+	fi
+	eval "$IFCONFIG $interface \
+		inet6 ${new_ip6_address}/${new_ip6_prefixlen} alias \
+		$medium"
+
+	$LOGGER "New IP Address ($interface): ${new_ip6_address}/${new_ip6_prefixlen}"
+	#$LOGGER "New Routers ($interface): $new_routers"
+}
+
 delete_old_alias() {
 	if [ -n "$alias_ip_address" ]; then
 		$IFCONFIG $interface inet -alias $alias_ip_address > /dev/null 2>&1
@@ -198,7 +228,7 @@
 	# thus broke the script. This code creates the resolv.conf if either
 	# are provided.
 
-	local tmpres=/var/run/resolv.conf.${interface}
+	local tmpres=/var/run/resolv.conf.${interface}.dhcp
 	rm -f $tmpres
 
 	if [ -n "$new_domain_search" ]; then
@@ -218,9 +248,9 @@
 			cat /etc/resolv.conf.tail >>$tmpres
 		fi
 
-		case $resolvconf_enable in
-		# "no", "false", "off", or "0"
-		[Nn][Oo]|[Ff][Aa][Ll][Ss][Ee]|[Oo][Ff][Ff]|0)
+		if resolvconf_enabled; then
+			$RESOLVCONF -a ${interface}.dhcp < $tmpres
+		else
 			# When resolv.conf is not changed actually, we don't
 			# need to update it.
 			# If /usr is not mounted yet, we cannot use cmp, then
@@ -244,12 +274,71 @@
 			# Try to ensure correct ownership and permissions.
 			chown -RL root:wheel /etc/resolv.conf
 			chmod -RL 644 /etc/resolv.conf
-			;;
+		fi
 
-		*)
-			/sbin/resolvconf -a ${interface} < $tmpres
-			;;
-		esac
+		rm -f $tmpres
+
+		return 0
+	fi
+
+	return 1
+}
+
+add_new_resolv_conf6() {
+	local tmpres=/var/run/resolv.conf.${interface}.dhcp6
+	rm -f $tmpres
+
+	if [ -n "$new_dhcp6_domain_search" ]; then
+		echo "search $new_dhcp6_domain_search" >>$tmpres
+	elif [ -n "$new_domain_name" ]; then
+		echo "search $new_domain_name" >>$tmpres
+	fi
+
+	if [ -n "$new_dhcp6_name_servers" ]; then
+		for nameserver in $new_dhcp6_name_servers; do
+		        # If the nameserver has a link-local address
+			# add a <zone_id> (interface name) to it.
+			case $nameserver in
+		    	fe80:*) zone_id="%$interface";;
+		        FE80:*) zone_id="%$interface";;
+			*)      zone_id="";;
+			esac
+			echo "nameserver ${nameserver}${zone_id}" >>$tmpres
+		done
+	fi
+
+	if [ -f $tmpres ]; then
+		if [ -f /etc/resolv.conf.tail ]; then
+			cat /etc/resolv.conf.tail >>$tmpres
+		fi
+
+		if resolvconf_enabled; then
+			$RESOLVCONF -a ${interface}.dhcp6 < $tmpres
+		else
+			# When resolv.conf is not changed actually, we don't
+			# need to update it.
+			# If /usr is not mounted yet, we cannot use cmp, then
+			# the following test fails.  In such case, we simply
+			# ignore an error and do update resolv.conf.
+			if cmp -s $tmpres /etc/resolv.conf; then
+				rm -f $tmpres
+				return 0
+			fi 2>/dev/null
+
+			# In case (e.g. during OpenBSD installs)
+			# /etc/resolv.conf is a symbolic link, take
+			# care to preserve the link and write the new
+			# data in the correct location.
+
+			if [ -f /etc/resolv.conf ]; then
+				cat /etc/resolv.conf > /etc/resolv.conf.save
+			fi
+			cat $tmpres > /etc/resolv.conf
+
+			# Try to ensure correct ownership and permissions.
+			chown -RL root:wheel /etc/resolv.conf
+			chmod -RL 644 /etc/resolv.conf
+		fi
 
 		rm -f $tmpres
 
@@ -321,6 +410,20 @@
 PREINIT)
 	delete_old_alias
 	$IFCONFIG $interface inet alias 0.0.0.0 netmask 255.0.0.0 broadcast 255.255.255.255 up
+	if resolvconf_enabled; then
+		$RESOLVCONF -d ${interface}.dhcp
+	fi
+	;;
+
+PREINIT6)
+	# Ensure interface is up.
+	ifconfig ${interface} up
+
+	# XXX: Remove any stale addresses from aborted clients.
+
+	if resolvconf_enabled; then
+		$RESOLVCONF -d ${interface}.dhcp6
+	fi
 	;;
 
 ARPCHECK|ARPSEND)
@@ -352,6 +455,41 @@
 	fi
 	;;
 
+BOUND6|RENEW6|REBIND6|REBOOT6)
+	check_hostname
+	if [ -n "$old_ip6_address" ]; then
+		if [ "$old_ip6_address" != "$new_ip6_address" ]; then
+			delete_old_address6
+			delete_old_routes6
+		fi
+	fi
+	if [ "$reason" = BOUND6 ] || \
+	   [ "$reason" = REBOOT6 ] || \
+	   [ -z "$old_ip6_address" ] || \
+	   [ "$old_ip6_address" != "$new_ip6_address" ]; then
+		add_new_address6
+	fi
+	if is_default_interface; then
+		add_new_resolv_conf6
+	fi
+	;;
+
+DEPREF6)
+	if [ -z ${new_ip6_address} ] ; then
+    		exit_with_hooks 2;
+	fi
+
+	ifconfig ${interface} inet6 ${new_ip6_address} deprecated
+	;;
+
+EXPIRE6|RELEASE6|STOP6)
+	if [ -z ${old_ip6_address} ] || [ -z ${old_ip6_prefixlen} ] ; then
+    		exit_with_hooks 2;
+	fi
+
+        delete_old_alias6
+	;;
+
 EXPIRE|FAIL)
 	delete_old_alias
 	if [ -n "$old_ip_address" ]; then
@@ -364,17 +502,13 @@
 	# XXX Why add alias we just deleted above?
 	add_new_alias
 	if is_default_interface; then
-		case $resolvconf_enable in
-		# "no", "false", "off", or "0"
-		[Nn][Oo]|[Ff][Aa][Ll][Ss][Ee]|[Oo][Ff][Ff]|0)
+		if resolvconf_enabled; then
+			$RESOLVCONF -d ${interface}.dhcp
+		else
 			if [ -f /etc/resolv.conf.save ]; then
 				cat /etc/resolv.conf.save > /etc/resolv.conf
 			fi
-			;;
-		*)
-			/sbin/resolvconf -d ${interface}
-			;;
-		esac
+		fi
 	fi
 	;;
 
@@ -402,6 +536,11 @@
 	delete_old_routes
 	exit_with_hooks 1
 	;;
+
+*)
+	$LOGGER "Unhandled DHCP event: $reason"
+	exit_with_hooks 1
+	;;
 esac
 
 exit_with_hooks 0
Index: share/man/man5/rc.conf.5
===================================================================
--- share/man/man5/rc.conf.5
+++ share/man/man5/rc.conf.5
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd June 8, 2016
+.Dd July 14, 2016
 .Dt RC.CONF 5
 .Os
 .Sh NAME
@@ -478,6 +478,47 @@
 .Dq Li SYNCDHCP
 or
 .Dq Li NOSYNCDHCP .
+.It Va dhclient6_program
+.Pq Vt str
+Path to the DHCP6 client program.
+There is currently no default DHCP6 client program.
+.It Va dhclient6_flags
+.Pq Vt str
+Additional flags to pass to the DHCP6 client program.
+.It Va dhclient6_flags_ Ns Aq Ar iface
+Additional flags to pass to the DHCP6 client program running on
+.Ar iface
+only.
+When specified, this variable overrides
+.Va dhclient6_flags .
+.It Va background_dhclient6
+.Pq Vt bool
+Set to
+.Dq Li YES
+to start the DHCP6 client in background.
+This can cause trouble with applications depending on
+a working network, but it will provide a faster startup
+in many cases.
+.It Va background_dhclient6_ Ns Aq Ar iface
+When specified, this variable overrides the
+.Va background_dhclient6
+variable for interface
+.Ar iface
+only.
+.It Va synchronous_dhclient6
+.Pq Vt bool
+Set to
+.Dq Li YES
+to start the DHCP6 client synchronously at startup.
+This behavior can be overridden on a per-interface basis by replacing
+the
+.Dq Li DHCP6
+keyword in the
+.Va ipv6_ Ns Aq Ar interface
+variable with
+.Dq Li SYNCDHCP6
+or
+.Dq Li NOSYNCDHCP6 .
 .It Va defaultroute_delay
 .Pq Vt int
 When set to a positive value, wait up to this long after configuring
@@ -948,7 +989,7 @@
 instances that should be started at system boot time.
 If
 .Va pflog_instances
-is set, for each whitespace-seperated
+is set, for each whitespace-separated
 .Ar element
 in the list,
 .Ao Ar element Ac Ns Va _dev
@@ -990,7 +1031,7 @@
 .Xr ftp-proxy 8
 are desired at boot time,
 .Va ftpproxy_instances
-should contain a whitespace-seperated list of instance names.
+should contain a whitespace-separated list of instance names.
 For each
 .Ar element
 in the list, a variable named
@@ -1389,6 +1430,19 @@
 ifconfig_ed0="DHCP"
 .Ed
 .Pp
+It is possible to bring up an interface with DHCPv6 by adding
+.Dq Li DHCP6
+to the
+.Va ipv6_ Ns Aq Ar interface
+variable.
+For instance, to initialize the
+.Li ed0
+device via DHCPv6,
+it is possible to use something like:
+.Bd -literal
+ipv6_ed0="DHCP6"
+.Ed
+.Pp
 If you want to configure your wireless interface with
 .Xr wpa_supplicant 8
 for use with WPA, EAP/LEAP or WEP, you need to add
@@ -2267,7 +2321,7 @@
 is set to
 .Dq Li YES ,
 run the nfsuserd daemon, which is needed for NFSv4 in order
-to map between user/group names vs uid/gid numbers.
+to map between user/group names versus uid/gid numbers.
 If
 .Va nfsv4_server_enable
 is set to
@@ -2770,7 +2824,7 @@
 .Pq Vt bool
 If set to
 .Dq Li YES ,
-configure host to act as an IP router, e.g.\& to forward packets
+configure host to act as an IP router, e.g.,\& to forward packets
 between interfaces.
 .It Va ipv6_gateway_enable
 .Pq Vt bool