diff --git a/olsrd/Makefile b/olsrd/Makefile
index 48dd7d2..e2686d0 100644
--- a/olsrd/Makefile
+++ b/olsrd/Makefile
@@ -37,7 +37,7 @@ define Package/olsrd
 endef
 
 define Package/olsrd/conffiles
-/etc/config/olsrd4
+/etc/config/olsrd
 /etc/config/olsrd6
 endef
 
@@ -173,41 +173,17 @@ define Package/olsrd/install
 	$(INSTALL_DIR) $(1)/lib/functions
 	$(INSTALL_DATA) ./files/olsrd.init $(1)/lib/functions/olsrd.sh
 	$(INSTALL_DIR) $(1)/etc/config
-	$(INSTALL_DATA) ./files/olsrd4.config $(1)/etc/config/olsrd4
+	$(INSTALL_DATA) ./files/olsrd.config $(1)/etc/config/olsrd
 	$(INSTALL_DATA) ./files/olsrd6.config $(1)/etc/config/olsrd6
 	$(INSTALL_DIR) $(1)/usr/sbin
 	$(INSTALL_BIN) $(PKG_BUILD_DIR)/olsrd $(1)/usr/sbin/
 	$(INSTALL_DIR) $(1)/etc/init.d
-	$(INSTALL_BIN) ./files/olsrd4.init $(1)/etc/init.d/olsrd4
+	$(INSTALL_BIN) ./files/olsrd4.init $(1)/etc/init.d/olsrd
 	$(INSTALL_BIN) ./files/olsrd6.init $(1)/etc/init.d/olsrd6
 	$(INSTALL_DIR) $(1)/etc/hotplug.d/iface
 	$(INSTALL_BIN) ./files/olsrd.hotplug.sh $(1)/etc/hotplug.d/iface/50-olsrd
 endef
 
-define Package/olsrd/preinst
-#!/bin/sh
-# check if we are on real system
-if [ -z "$${IPKG_INSTROOT}" ]; then
-	[ -f /etc/config/olsrd ] && cp /etc/config/olsrd /etc/config/olsrd.opkg-old
-fi
-exit 0
-endef
-
-define Package/olsrd/postinst
-#!/bin/sh
-# check if we are on real system
-if [ -z "$${IPKG_INSTROOT}" ]; then
-        if [ -f /etc/config/olsrd.opkg-old ]; then
-		mv /etc/config/olsrd.opkg-old /etc/config/olsrd
-		echo "**********  WARNING  ***************"
-		echo "/etc/config/olsrd is no longer used! This will prevent olsrd to start."
-		echo "Please use /etc/config/olsrd4 for IPv4 and /etc/config/olrsd6 for IPv6"
-		echo "Remember to remove option IpVersion from your config file"
-	fi
-fi
-exit 0
-endef
-
 define Package/olsrd-mod-arprefresh/install
 	$(INSTALL_DIR) $(1)/usr/lib
 	$(INSTALL_BIN) $(PKG_BUILD_DIR)/lib/arprefresh/olsrd_arprefresh.so.* $(1)/usr/lib/
diff --git a/olsrd/files/olsrd4.config b/olsrd/files/olsrd.config
similarity index 100%
rename from olsrd/files/olsrd4.config
rename to olsrd/files/olsrd.config
diff --git a/olsrd/files/olsrd.hotplug.sh b/olsrd/files/olsrd.hotplug.sh
index 9e5f0ca..99e834e 100755
--- a/olsrd/files/olsrd.hotplug.sh
+++ b/olsrd/files/olsrd.hotplug.sh
@@ -52,7 +52,7 @@ case "$ACTION" in
 	ifup)
 		# only work after the first normal startup
 		# also: no need to test, if enabled
-	        OLSRD=olsrd4
+	        OLSRD=olsrd
 		[ -e "/var/etc/$OLSRD.conf" ] && {
 			# INTERFACE = e.g. 'wlanadhocRADIO1' or 'cfg144d8f'
 			# DEVICE    = e.g. 'wlan1-1'
diff --git a/olsrd/files/olsrd.init b/olsrd/files/olsrd.init
index 5864756..887a4a2 100644
--- a/olsrd/files/olsrd.init
+++ b/olsrd/files/olsrd.init
@@ -15,13 +15,19 @@ OLSRD_INTERFACE_DEFAULTS_SCHEMA='AutoDetectChanges:bool'
 T='	'
 N='
 '
+#6and4: backward compatibility - it MUST be different from /etc/init.d/olsrd6 PID variable
+PID6=/var/run/olsrd6and4.pid
 
 log() {
 	logger -t olsrd -p daemon.info -s "${initscript}: $@"
 }
 
 error() {
-	log "ERROR: $@"
+        logger -t olsrd -p daemon.err -s "${initscript}: ERROR: $@"
+}
+
+warn() {
+        logger -t olsrd -p daemon.warn -s "${initscript}: WARNING: $@"
 }
 
 validate_varname() {
@@ -391,6 +397,18 @@ olsrd_write_olsrd() {
 	[ "$OLSRD_COUNT" -gt 0 ] && return 0
 
 	config_get ipversion "$cfg" IpVersion
+	if [ "$UCI_CONF_NAME" == "olsrd6" ]; then
+	        OLSRD_OLSRD_SCHEMA="$OLSRD_OLSRD_SCHEMA IpVersion=6"
+	        if [ "$ipversion" = "6and4" ]; then
+		        error "IpVersion 6and4 not supported in olsrd6"
+			return 1
+		fi
+	else
+	        if [ "$ipversion" = "6and4" ]; then
+		        OLSRD_IPVERSION_6AND4=1
+			config_set "$cfg" IpVersion '6'
+		fi
+	fi
 	config_get smartgateway "$cfg" SmartGateway
 	config_get smartgatewayuplink "$cfg" SmartGatewayUplink
 
@@ -614,21 +632,9 @@ olsrd_update_schema() {
 }
 
 olsrd_write_config() {
+	OLSRD_IPVERSION_6AND4=0
 	OLSRD_COUNT=0
 	config_foreach olsrd_write_olsrd olsrd
-
-	if [ ! -z "$ipversion" ]; then
-	        if [ "$ipversion" = "6and4" ]; then
-		        error "IpVersion 6and4 is no longer supported!"
-			error "You must use /etc/config/olsrd4 for IPv4 and /etc/config/olsrd6 for IPv4"
-		else
-	                error "Option IpVersion is no longer supported!"
-		        error "Please remove it from /etc/config/$UCI_CONF_NAME"
-		fi
-
-		return 1
-	fi
-
 	IPCCONNECT_COUNT=0
 	config_foreach olsrd_write_ipcconnect IpcConnect
 	HNA4_COUNT=0
@@ -754,13 +760,6 @@ olsrd_setup_smartgw_rules() {
 }
 
 start() {
-        if [ -f /etc/config/olsrd ]; then
-	       error "/etc/config/olsrd no longer supported!"
-	       error "please move your config file to /etc/config/olsrd4 and/or /etc/config/olsrd6"
-
-	       return 1
-	fi
-
 	SYSTEM_HOSTNAME=
 	SYSTEM_LAT=
 	SYSTEM_LON=
@@ -793,16 +792,53 @@ start() {
 
 	[ -z "$OLSRD_CONFIG_FILE" ] && return 1
 
-	SERVICE_PID_FILE="$PID"
-	if service_check /usr/sbin/olsrd; then
-		error "there is already an instance of $UCI_CONF_NAME running (pid: '$(cat $PID)'), not starting."
-		return 1
+	#6and4: backward compatibility
+	local bindv6only='0'
+	if [ "$OLSRD_IPVERSION_6AND4" -ne 0 ]; then
+	        warn "IpVersion 6and4 is deprecated and will be removed in future!"
+		warn "You must use /etc/config/olsrd and /etc/init.d/olsrd for IPv4"
+		warn " /etc/config/olsrd6 and /etc/init.d/olsrd6 for IPv6"
+
+		bindv6only="$(sysctl -n net.ipv6.bindv6only)"
+		sysctl -w net.ipv6.bindv6only=1 > /dev/null
+		sed -e '/[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}/d' < "$OLSRD_CONFIG_FILE" > /var/etc/olsrd.conf.ipv6
+		sed -e 's/^IpVersion[ ][ ]*6$/IpVersion 4/' -e 's/^\t\t[A-Fa-f0-9.:]*[:][A-Fa-f0-9.:]*[ ][0-9]*$//' < "$OLSRD_CONFIG_FILE" > /var/etc/olsrd.conf.ipv4
+		rm $OLSRD_CONFIG_FILE
+
+		# some filenames should get the suffix .ipv6
+		for file in $latlon_file $hosts_file $services_file $resolv_file $macs_file $wd_file;do
+			f=$(echo $file|sed 's/\//\\\//g')
+			sed -i "s/$f/$f.ipv6/g" /var/etc/olsrd.conf.ipv6
+		done
+
+		SERVICE_PID_FILE="$PID6"
+		if service_check /usr/sbin/olsrd; then
+			error "there is already an IPv6 instance of olsrd running (pid: '$(cat $PID6)'), not starting."
+		else
+			service_start /usr/sbin/olsrd -f /var/etc/olsrd.conf.ipv6 -nofork
+		fi
+
+		SERVICE_PID_FILE="$PID"
+		if service_check /usr/sbin/olsrd; then
+			error "there is already an IPv4 instance of olsrd running (pid: '$(cat $PID)'), not starting."
+		else
+			service_start /usr/sbin/olsrd -f /var/etc/olsrd.conf.ipv4 -nofork
+		fi
+
+		sleep 3
+		sysctl -w net.ipv6.bindv6only="$bindv6only" > /dev/null
 	else
-		service_start /usr/sbin/olsrd -f "$OLSRD_CONFIG_FILE" -nofork
-		sleep 1
-		service_check /usr/sbin/olsrd || {
-			log "startup-error: check via: '/usr/sbin/olsrd -f \"$OLSRD_CONFIG_FILE\" -nofork'"
-		}
+		SERVICE_PID_FILE="$PID"
+		if service_check /usr/sbin/olsrd; then
+			error "there is already an instance of $UCI_CONF_NAME running (pid: '$(cat $PID)'), not starting."
+			return 1
+		else
+			service_start /usr/sbin/olsrd -f "$OLSRD_CONFIG_FILE" -nofork
+			sleep 1
+			service_check /usr/sbin/olsrd || {
+				log "startup-error: check via: '/usr/sbin/olsrd -f \"$OLSRD_CONFIG_FILE\" -nofork'"
+			}
+		fi
 	fi
 
 	olsrd_setup_smartgw_rules
@@ -811,4 +847,8 @@ start() {
 stop() {
 	SERVICE_PID_FILE="$PID"
 	service_stop /usr/sbin/olsrd
+
+	#6and4: backward compatibility
+	SERVICE_PID_FILE="$PID6"
+	service_stop /usr/sbin/olsrd
 }
diff --git a/olsrd/files/olsrd4.init b/olsrd/files/olsrd4.init
index 9b08f2d..09adf6d 100644
--- a/olsrd/files/olsrd4.init
+++ b/olsrd/files/olsrd4.init
@@ -8,8 +8,7 @@ START=65
 SERVICE_DAEMONIZE=1
 SERVICE_WRITE_PID=1
 
-CONF=/var/etc/olsrd4.conf
+CONF=/var/etc/olsrd.conf
 PID=/var/run/olsrd4.pid
 
-UCI_CONF_NAME=olsrd4
-OLSRD_OLSRD_SCHEMA="$OLSRD_OLSRD_SCHEMA IpVersion=4"
+UCI_CONF_NAME=olsrd
diff --git a/olsrd/files/olsrd6.init b/olsrd/files/olsrd6.init
index c43cc03..1dcc4a0 100644
--- a/olsrd/files/olsrd6.init
+++ b/olsrd/files/olsrd6.init
@@ -12,4 +12,3 @@ CONF=/var/etc/olsrd6.conf
 PID=/var/run/olsrd6.pid
 
 UCI_CONF_NAME=olsrd6
-OLSRD_OLSRD_SCHEMA="$OLSRD_OLSRD_SCHEMA IpVersion=6"