ipv6 update (<pekkas@netcore.fi>)

6 files changed, 167 insertions, 164 deletions

diff --git a/sysconfig/network-scripts/ifdown-ipv6 b/sysconfig/network-scripts/ifdown-ipv6
index d111d1cb..8f4319ba 100755
--- a/sysconfig/network-scripts/ifdown-ipv6
+++ b/sysconfig/network-scripts/ifdown-ipv6
@@ -8,7 +8,7 @@
 #
 # RHL integration assistance by Pekka Savola <pekkas@netcore.fi>
 #
-# Version 2001-05-22d
+# Version 2001-07-15
 #
 # Uses following information from /etc/sysconfig/network:
 #  NETWORKING_IPV6=yes|no: controls IPv6 initialization (global setting)
@@ -36,14 +36,10 @@ CONFIG=$1
 [ -f "$CONFIG" ] || CONFIG=ifcfg-$CONFIG
 source_config                                                                   
 
-# Test if IPv6 is globally enabled
-if [ ! "${NETWORKING_IPV6}" = "yes" ]; then
-        # Global IPv6 switch not enabled, end now
-        exit 0
-fi
+# Test whether IPv6 should be configured, else stop
+[ "${NETWORKING_IPV6}" = "yes" ] || exit 0
 
 if [ ! -f /etc/sysconfig/network-scripts/network-functions-ipv6 ]; then
-	# IPv6 setup isn't well
 	exit 1
 fi
 
@@ -68,7 +64,6 @@ if [ "$valid6to4config" = "yes" ]; then
 	if [ "$IPV6TO4_CONTROL_RADVD" = "yes" ]; then
 		# stop RADVD from distributing no longer usable 6to4 prefixes
 		if [ -z "$IPV6TO4_RADVD_PIDFILE" ]; then
-			# Take default
 			IPV6TO4_RADVD_PIDFILE="/var/run/radvd/radvd.pid"
 		fi
 		# Send SIGHUP to radvd
@@ -92,8 +87,43 @@ if [ "$valid6to4config" = "yes" ]; then
 		done
 	fi
 
+	# Detect type of address, whether it is IPv4 or IPv6
+	if testipv6_valid $IPV6TO4_RELAY; then
+		relay6to4type="ipv6"
+	fi
+
 	# Delete all static IPv6to4 routes
-	ifdown_ipv6_route_all sit0 ::$IPV6TO4_RELAY
+	if [ "$relay6to4type" = "ipv6" ]; then	
+		ifdown_ipv6_route_all sit0 $IPV6TO4_RELAY
+	else
+		ifdown_ipv6_route_all sit0 ::$IPV6TO4_RELAY
+	fi
+
+	# Delete old 6to4 routes, even if IPV6TO4_RELAY was changed
+	if [ -f /etc/sysconfig/static-routes-ipv6 ]; then
+		grep -w "^sit0" /etc/sysconfig/static-routes-ipv6 | while read device network dummy; do
+			if [ "$EXISTS_ipv6calc" = "yes" ]; then
+				# Convert given network to compressed one
+				network="`ipv6calc  --addr_to_compressed $network`"
+			fi
+			LC_ALL=C route -A inet6 | grep "^$network" | while read destination nexthop flags metric ref use iface dummy; do
+				if ! [ "$device" = "$iface" -a "$network" = "$destination" ]; then
+					continue
+				fi
+				# Look for routes to a compatible IPv4 address, delete them
+				if echo $nexthop | egrep -q '^::[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$'; then
+					ifdown_ipv6_route $destination $nexthop $iface
+				fi
+				# Look for routes to a IPv6to4 address, delete them
+				if echo $nexthop | egrep -q '^2002::'; then
+					ifdown_ipv6_route $destination $nexthop $iface
+				fi
+			done
+		done
+	fi
+
+	# Delete 6to4 route
+	ifdown_ipv6_route 2002::/16 :: sit0
 
 	# Delete all configured 6to4 address
 	ifdown_ipv6to4_all sit0 
diff --git a/sysconfig/network-scripts/ifdown-sit b/sysconfig/network-scripts/ifdown-sit
index a2a70c16..1fa4dad9 100755
--- a/sysconfig/network-scripts/ifdown-sit
+++ b/sysconfig/network-scripts/ifdown-sit
@@ -8,7 +8,7 @@
 #
 # RHL integration assistance by Pekka Savola <pekkas@netcore.fi>
 #
-# Version 2001-05-22d
+# Version 2001-07-15a
 #
 # Uses following information from /etc/sysconfig/network:
 #  NETWORKING_IPV6=yes|no: controls IPv6 initialization (global setting)
@@ -31,14 +31,10 @@ CONFIG=$1
 [ -f "$CONFIG" ] || CONFIG=ifcfg-$CONFIG
 source_config                                                                   
 
-# Test if IPv6 is up
-if [ ! "${NETWORKING_IPV6}" = "yes" ]; then
-        # Global IPv6 switch not enabled, end now
-        exit 0
-fi
+# Test whether IPv6 should be configured, else stop
+[ "${NETWORKING_IPV6}" = "yes" ] || exit 0
 
 if [ ! -f /etc/sysconfig/network-scripts/network-functions-ipv6 ]; then
-	# IPv6 setup isn't well
 	exit 1
 fi
 
@@ -54,7 +50,6 @@ if [ "$DEVICE" = "sit0" ]; then
 elif [ ! -z "$IPV6TUNNELIPV4" ]; then
 	if [ "$IPV6_TUNNELMODE" = "NBMA" ]; then
         	if [ ! -z "$IPV6ADDR" ]; then
-			# Numbered tunnel
 			ifdown_ipv6_real sit0 $IPV6ADDR
 		fi
 
diff --git a/sysconfig/network-scripts/ifup-ipv6 b/sysconfig/network-scripts/ifup-ipv6
index b8a5c71c..cd5d0062 100755
--- a/sysconfig/network-scripts/ifup-ipv6
+++ b/sysconfig/network-scripts/ifup-ipv6
@@ -8,7 +8,7 @@
 #
 # RHL integration assistance by Pekka Savola <pekkas@netcore.fi>
 #
-# Version 2001-05-22d
+# Version 2001-07-16
 #
 # Uses following information from "/etc/sysconfig/network":
 #  NETWORKING_IPV6=yes|no: controls IPv6 initialization (global setting)
@@ -22,10 +22,11 @@
 #   defaults:
 #    IPV6FORWARDING=yes: IPV6_AUTOCONF=no, IPV6_ROUTER=yes
 #    IPV6FORWARDING=no: IPV6_AUTOCONF=yes
+#  IPV6_MTU=<MTU for IPv6>: controls IPv6 MTU for this link [optional]
 #
 # Optional for 6to4 tunneling:
 #  IPV6TO4INIT=yes|no: controls 6to4 tunneling setup
-#  IPV6TO4_RELAY=<ipv4address>: IPv4 address of the remote 6to4 relay
+#  IPV6TO4_RELAY=<ipv4address|ipv6to4address>: IPv4/IPv6to4 address of the remote 6to4 relay
 #  IPV6TO4_IPV4ADDR=<ipv6address>: overwrite local IPv4 address [optional]
 #  IPV6TO4_ROUTING="eth0-:f101::0/64 eth1-:f102::0/64": information to setup local subnetting
 #  IPV6TO4_CONTROL_RADVD=yes|no: controls radvd triggering [optional]
@@ -47,20 +48,13 @@ CONFIG=$1
 [ -f "$CONFIG" ] || CONFIG=ifcfg-$CONFIG
 source_config  
 
-# Test if IPv6 configuration is enabled
-if [ ! "$IPV6INIT" = "yes" ]; then
-	# not enabled, stop here
-	exit 0
-fi                                                  
+# Test whether IPv6 configuration is enabled for this interface, else stop
+[ "$IPV6INIT" = "yes" ] || exit 0
 
-# Test if IPv6 is up
-if [ ! "${NETWORKING_IPV6}" = "yes" ]; then
-	# Global IPv6 switch not enabled, end now
-	exit 0
-fi
+# Test whether IPv6 should be configured, else stop
+[ "${NETWORKING_IPV6}" = "yes" ] || exit 0
 
 if [ ! -f /etc/sysconfig/network-scripts/network-functions-ipv6 ]; then
-	# IPv6 setup isn't well
 	exit 1
 fi
 
@@ -85,19 +79,16 @@ if [ "$IPV6FORWARDING" = "yes" ]; then
 
 	# Check, if global IPv6 forwarding was already set by global script
 	if [ $ipv6_global_forwarding_current -ne 1 ]; then
-		# Forwarding enabled, but not set, display warning
 		echo $"Global IPv6 forwarding is enabled in configuration, but not currently enabled in kernel"
-		echo $"Please restart network with '/etc/rc.d/init.d/network restart'"
+#		echo $"Please restart network with '/sbin/service network restart'"
 	fi
 
 	ipv6_local_forwarding=1
 	ipv6_local_auto=0
 	if [ "$IPV6_ROUTER" = "no" ]; then
-		# Interface should not act as a Router
 		ipv6_local_forwarding=0
 	fi
 	if [ "$IPV6_AUTOCONF" = "yes" ]; then
-		# Interface should be autoconfigured
 		ipv6_local_auto=1
 	fi
 else
@@ -105,15 +96,13 @@ else
 
 	# Check, if global IPv6 forwarding was already set by global script
 	if [ $ipv6_global_forwarding_current -ne 0 ]; then
-		# Forwarding disabled, but not set, display warning
 		echo $"Global IPv6 forwarding is disabled in configuration, but not currently disabled in kernel"
-		echo $"Please restart network with '/etc/rc.d/init.d/network restart'"
+#		echo $"Please restart network with '/sbin/service network restart'"
 	fi
 
 	ipv6_local_forwarding=0
 	ipv6_local_auto=1
 	if [ "$IPV6_AUTOCONF" = "no" ]; then
-		# Interface should not be autoconfigured
 		ipv6_local_auto=0
 	fi
 fi
@@ -121,6 +110,11 @@ sysctl -w net.ipv6.conf.$DEVICE.forwarding=$ipv6_local_forwarding >/dev/null
 sysctl -w net.ipv6.conf.$DEVICE.accept_ra=$ipv6_local_auto >/dev/null
 sysctl -w net.ipv6.conf.$DEVICE.accept_redirects=$ipv6_local_auto >/dev/null
 
+# Set IPv6 MTU, if given
+if [ ! -z "$IPV6_MTU" ]; then
+	ipv6_set_mtu $DEVICE $IPV6_MTU
+fi
+
 # Setup additional IPv6 addresses from list
 if [ ! -z "$IPV6ADDR_SECONDARIES" ]; then
 	for ipv6addr in $IPV6ADDR_SECONDARIES; do
@@ -130,10 +124,8 @@ fi
 
 # Setup additional static IPv6 routes on specified interface
 if [ -f /etc/sysconfig/static-routes-ipv6 ]; then
-	grep "^$DEVICE\W" /etc/sysconfig/static-routes-ipv6 | while read device args; do
-		if [ "$device" = "$DEVICE" ]; then
-			ifup_ipv6_route $args $DEVICE
-		fi
+	grep -w "^$DEVICE" /etc/sysconfig/static-routes-ipv6 | while read device args; do
+		ifup_ipv6_route $args $DEVICE
 	done
 fi
 
@@ -152,7 +144,6 @@ if [ "$IPV6TO4INIT" = "yes" ]; then
 		fi
         fi
 	if [ ! -z "$ipv4addr" ]; then
-		# Test for non-global IPv4 address 
 		if ! testipv4_globalusable $ipv4addr; then
 			echo $"Given IPv4 address $ipv4addr is not a globally usable one, 6to4 configuration is not valid!"
 	                valid6to4config="no"
@@ -162,8 +153,19 @@ if [ "$IPV6TO4INIT" = "yes" ]; then
 			valid6to4config="no"
 		fi
 		if [ "$valid6to4config" = "yes" ]; then
-			if ! testipv4_globalusable $IPV6TO4_RELAY; then
-				echo $"Given IPv4 address of relay is not a globally usable one, 6to4 configuration is not valid!"
+			if testipv4_globalusable $IPV6TO4_RELAY 2>/dev/null; then
+				true
+			elif testipv6_valid $IPV6TO4_RELAY; then
+				relay6to4type="ipv6"
+				if echo $IPV6TO4_RELAY | grep -q "^2002:"; then
+					# IPv6 address is a 6to4 (further tests not be implemented at the moment)
+					true
+				else
+					echo $"Given IPv6 address of relay is not a 6to4 one, 6to4 configuration is not valid!"
+					valid6to4config="no"
+				fi
+			else
+				echo $"Given address of relay is not a globally usable one, 6to4 configuration is not valid!"
 				valid6to4config="no"
 			fi
 		fi
@@ -173,27 +175,31 @@ if [ "$IPV6TO4INIT" = "yes" ]; then
 	fi
         if [ "$valid6to4config" = "yes" ]; then
 		ifup_ipv6to4 $DEVICE $ipv4addr
+
+		# Add static routes
 		if [ -f /etc/sysconfig/static-routes-ipv6 ]; then
-			grep "^sit0" /etc/sysconfig/static-routes-ipv6 | while read device args; do
-				if [ "$device" = "sit0" ]; then
-					ifup_ipv6_route $args ::$IPV6TO4_RELAY sit0
+			grep -w "^sit0" /etc/sysconfig/static-routes-ipv6 | while read device network dummy; do
+				if [ "$relay6to4type" = "ipv6" ]; then
+					# Foreign 6to4 relay gateway as IPv6to4 
+					ifup_ipv6_route $network $IPV6TO4_RELAY sit0
+				else
+					# Foreign 6to4 relay gateway as compatible IPv4 
+					ifup_ipv6_route $network ::$IPV6TO4_RELAY sit0
 				fi
 			done
 		fi
 
 	        if [ "$IPV6TO4_CONTROL_RADVD" = "yes" ]; then
-			# RADVD is in use, so forwarding of IPv6 packets should be enabled
+			# RADVD is in use, so forwarding of IPv6 packets should be enabled, display warning
 			if [ $ipv6_global_forwarding_current -ne 1 ]; then
-				# Forwarding not set, display warning
 				echo $"Using 6to4 and RADVD IPv6 forwarding usually should be enabled, but it isn't!"
 			fi
 
 			if [ -z "$IPV6TO4_RADVD_PIDFILE" ]; then
-				# Take default
 				IPV6TO4_RADVD_PIDFILE="/var/run/radvd/radvd.pid"
 			fi
 
-			# Send SIGHUP to radvd
+			# Send SIGHUP to radvd for prefix recalculation
 			if [ -f "$IPV6TO4_RADVD_PIDFILE" ]; then
 				pid="`cat $IPV6TO4_RADVD_PIDFILE`"
 				if [ ! -z "$pid" ]; then
@@ -204,7 +210,6 @@ if [ "$IPV6TO4INIT" = "yes" ]; then
 				fi
 			fi
 		        if [ ! -z "$IPV6TO4_ROUTING" ]; then
-				# Generate 6to4 address
 				ipv6to4prefix="`create6to4prefix $ipv4addr`"
 				if [ ! -z "$ipv6to4prefix" ]; then
 					# Add route to local networks
diff --git a/sysconfig/network-scripts/ifup-sit b/sysconfig/network-scripts/ifup-sit
index baf78a66..15ed67cd 100755
--- a/sysconfig/network-scripts/ifup-sit
+++ b/sysconfig/network-scripts/ifup-sit
@@ -8,7 +8,7 @@
 #
 # RHL integration assistance by Pekka Savola <pekkas@netcore.fi>
 #
-# Version 2001-05-22d
+# Version 2001-07-17
 #
 # Uses following information from "/etc/sysconfig/network":
 #  NETWORKING_IPV6=yes|no: controls IPv6 initialization (global setting)
@@ -16,6 +16,7 @@
 # Uses following information from "/etc/sysconfig/network-scripts/ifcfg-$1":
 #  IPV6INIT=yes|no: controls IPv6 configuration for this interface
 #  IPV6_TUNNELMODE=IP|NBMA: mode of tunnel creation [default: IP]
+#  IPV6_MTU=<MTU for IPv6>: controls IPv6 MTU for this link [optional]
 # 
 #  For static tunnels 
 #  IPV6TUNNELIPV4="<ipv4 address of foreign tunnel endpoint>"
@@ -34,18 +35,13 @@ CONFIG=$1
 [ -f "$CONFIG" ] || CONFIG=ifcfg-$CONFIG
 source_config  
 
-# Test if IPv6 configuration is enabled for this interface
-if [ ! "$IPV6INIT" = "yes" ]; then
-	exit 0
-fi                                                  
+# Test whether IPv6 configuration is enabled for this interface, else stop
+[ "$IPV6INIT" = "yes" ] || exit 0
 
-# Test if IPv6 is up
-if [ ! "${NETWORKING_IPV6}" = "yes" ]; then
-        exit 0
-fi
+# Test whether IPv6 should be configured, else stop
+[ "${NETWORKING_IPV6}" = "yes" ] || exit 0
 
 if [ ! -f /etc/sysconfig/network-scripts/network-functions-ipv6 ]; then
-	# IPv6 setup isn't well
 	exit 1
 fi
 
@@ -58,36 +54,45 @@ test_ipv6 || exit 1
 # Setup IPv6-in-IPv4 tunnel(s)
 if [ "$DEVICE" = "sit0" ]; then
 	ifup_ipv6_autotunnel || exit 1
+	
+	# Set IPv6 MTU, if given 
+	if [ ! -z "$IPV6_MTU" ]; then
+		ipv6_set_mtu $DEVICE $IPV6_MTU
+	fi
 
 elif [ ! -z "$IPV6TUNNELIPV4" ]; then
 	if [ "$IPV6_TUNNELMODE" = "NBMA" ]; then
-		# NBMA-styled tunneling
 		if [ ! -z "$IPV6ADDR" ]; then
-			# Numbered tunnel
 			ifup_ipv6_real sit0 $IPV6ADDR
 		fi
 
 		# Add static IPv6 tunnel routes on specified virtual interface
 		if [ -f /etc/sysconfig/static-routes-ipv6 ]; then
-			grep "^$DEVICE" /etc/sysconfig/static-routes-ipv6 | while read device ipv6route args; do
-				if [ "$device" = "$DEVICE" ]; then
-					ifup_ipv6_tunnel $DEVICE $IPV6TUNNELIPV4 $ipv6route
-				fi
+			grep -w "^$DEVICE" /etc/sysconfig/static-routes-ipv6 | while read device ipv6route args; do
+				ifup_ipv6_tunnel $DEVICE $IPV6TUNNELIPV4 $ipv6route
 			done
 		fi
+
+		# Set IPv6 MTU, if given and in range
+		if [ ! -z "$IPV6_MTU" ]; then
+			ipv6_set_mtu sit0 $IPV6_MTU
+		fi
+
 	elif [ -z "$IPV6_TUNNELMODE" -o "$IPV6_TUNNELMODE" = "IP" ]; then
 		ifup_ipv6_tunneldev $DEVICE $IPV6TUNNELIPV4 || exit 1
 
+		# Set IPv6 MTU, if given and in range
+		if [ ! -z "$IPV6_MTU" ]; then
+			ipv6_set_mtu $DEVICE $IPV6_MTU
+		fi
+
 		if [ ! -z "$IPV6ADDR" ]; then
-			# Numbered tunnel
 			ifup_ipv6_real $DEVICE $IPV6ADDR
 		fi
 			
 		if [ -f /etc/sysconfig/static-routes-ipv6 ]; then
-			grep "^$DEVICE\W" /etc/sysconfig/static-routes-ipv6 | while read device ipv6route args; do
-				if [ "$device" = "$DEVICE" ]; then
-					ifup_ipv6_route $ipv6route :: $DEVICE
-				fi
+			grep -w "^$DEVICE" /etc/sysconfig/static-routes-ipv6 | while read device ipv6route args; do
+				ifup_ipv6_route $ipv6route :: $DEVICE
 			done
 		fi
 	else
diff --git a/sysconfig/network-scripts/init.ipv6-global b/sysconfig/network-scripts/init.ipv6-global
index da46d4ba..aed005d8 100755
--- a/sysconfig/network-scripts/init.ipv6-global
+++ b/sysconfig/network-scripts/init.ipv6-global
@@ -8,7 +8,7 @@
 #
 # RHL integration assistance by Pekka Savola <pekkas@netcore.fi>
 #
-# Version 2001-05-22d
+# Version 2001-07-15a
 #
 # Calling parameters:
 #  $1: action (currently supported: start|stop|showsysctl)
@@ -37,10 +37,8 @@ cd /etc/sysconfig/network-scripts
 ACTION="$1"
 POSITION="$2"
 
-# Test for IPv6 enabling
-if [ ! "${NETWORKING_IPV6}" = "yes" ]; then
-	exit 0
-fi
+# Test whether IPv6 should be configured, else stop
+[ "${NETWORKING_IPV6}" = "yes" ] || exit 0
 
 if [ ! -f /etc/sysconfig/network-scripts/network-functions-ipv6 ]; then
 	exit 1
diff --git a/sysconfig/network-scripts/network-functions-ipv6 b/sysconfig/network-scripts/network-functions-ipv6
index 6b4441a8..82c8d020 100644
--- a/sysconfig/network-scripts/network-functions-ipv6
+++ b/sysconfig/network-scripts/network-functions-ipv6
@@ -5,7 +5,7 @@
 # Taken from:
 # (P) & (C) 1997-2001 by Peter Bieringer <pb@bieringer.de>
 #
-# Version: 2001-05-22d
+# Version: 2001-07-17a
 #
 # Extended address detection is enabled, if 'ipv6calc' is installed
 #  Available here: http://www.bieringer.de/linux/IPv6/tools/index.html#ipv6calc
@@ -23,7 +23,6 @@
 ##### Test for "ipv6calc" (used for better existing address detection)
 EXISTS_ipv6calc=no	
 	if which ipv6calc >/dev/null 2>&1; then
-		# do checks, whether ipv6calc does what was expected
 		if ipv6calc --if_inet62addr 3ffe04000100f1010000000000000001 40 | grep -q -v '3ffe:400:100:f101::1/64'; then
 			false
 		elif ipv6calc --addr2if_inet6 3ffe:400:100::1/64 | grep -q -v '3ffe0400010000000000000000000001 00 40'; then
@@ -42,7 +41,6 @@ test_ipv6() {
 	local testflag=$1
 
 
-	# Test for IPv6 enabled kernel
 
 	if ! [ -f /proc/net/if_inet6 ]; then
 		if [ "$testflag" = "testonly" ]; then
@@ -58,7 +56,6 @@ test_ipv6() {
 	fi
 
 	if [ ! -d /proc/sys/net/ipv6/conf/ ]; then
-		# IPv6 related proc directory doesn't exist 
 		return 2
 	fi
 
@@ -98,7 +95,6 @@ forwarding_ipv6() {
 		return 1
 	fi
 	
-	# Run IPv6 test
 	test_ipv6 || return 2   
 
 
@@ -142,16 +138,10 @@ ifup_ipv6_route() {
 		return 1
 	fi
 
-	# Run IPv6 test
 	test_ipv6 || return 2   
 
-	# Test, whether given IPv6 address is valid	
-	if ! testipv6_valid $networkipv6; then
-		return 2
-	fi
-	if ! testipv6_valid $gatewayipv6; then
-		return 2
-	fi
+	testipv6_valid $networkipv6 || return 2
+	testipv6_valid $gatewayipv6 || return 2
 
 	
 	if [ -z "$device" ]; then
@@ -195,16 +185,11 @@ ifdown_ipv6_route() {
 		return 1
 	fi
 
-	# Run IPv6 test
 	test_ipv6 || return 2
 
 	# Test, whether given IPv6 address is valid	
-	if ! testipv6_valid $networkipv6; then
-		return 2
-	fi
-	if ! testipv6_valid $gatewayipv6; then
-		return 2
-	fi
+	testipv6_valid $networkipv6 || return 2
+	testipv6_valid $gatewayipv6 || return 2
 
 	
 	if [ -z "$device" ]; then
@@ -241,7 +226,6 @@ ifdown_ipv6_route_all() {
 		return 1
 	fi
 
-	# Run IPv6 test
 	test_ipv6 || return 2   
 
 
@@ -251,7 +235,6 @@ ifdown_ipv6_route_all() {
 			if [ ! -z "$gatewaymatch" ]; then
 				# Test if given gateway matches
 				if [ "$gatewaymatch" != "$nexthop" ]; then
-					# No match, take next
 					continue
 				fi
 			fi
@@ -269,19 +252,16 @@ ifdown_ipv6_route_all() {
 
 ## Configure automatic tunneling up
 ifup_ipv6_autotunnel() {
-	# Run IPv6 test
 	test_ipv6 || return 2 
 
 
 	# enable IPv6-over-IPv4 tunnels
 	if test_interface_status sit0; then
-		# already up, do nothing
 		true
 	else
-		# basic tunnel device to up
+		# bring up basic tunnel device
 			ifconfig sit0 up
 
-			# Test, whether "up" has worked
 			if ! test_interface_status sit0; then
 				echo $"Tunnel device 'sit0' enabling didn't work - FATAL ERROR!"
 				return 2
@@ -299,12 +279,10 @@ ifup_ipv6_autotunnel() {
 
 ## Configure automatic tunneling down
 ifdown_ipv6_autotunnel() {
-	# Run IPv6 test
 	test_ipv6 || return 2
 
 
 	if test_interface_status sit0; then
-		# still up?
 
 		# disable IPv6-over-IPv4 tunnels (if a tunnel is no longer up)
 		if LC_ALL=C route -A inet6 -n | grep "sit0\W*$" | awk '{ print $2 }' | grep -v -q "^::$"; then
@@ -314,15 +292,13 @@ ifdown_ipv6_autotunnel() {
 			# still existing IPv6 addresses, skip shutdown of sit0
 			true
 		else
-			# basic tunnel device to down
-				# Set sysctls proper 
+			# take down basic tunnel device
 				sysctl -w net.ipv6.conf.sit0.forwarding=0 >/dev/null
 				sysctl -w net.ipv6.conf.sit0.accept_ra=0 >/dev/null
 				sysctl -w net.ipv6.conf.sit0.accept_redirects=0 >/dev/null
 			
 				ifconfig sit0 down
 
-				# Test, whether "down" has worked
 				if test_interface_status sit0; then
 					echo $"Tunnel device 'sit0' is still up - FATAL ERROR!"
 					return 2
@@ -351,7 +327,7 @@ ifup_ipv6_tunnel() {
 	fi
 
 	if [ -z "$addressipv4tunnel" ]; then
-		echo $"Missing parameter 'IPv4-tunneladdress' (arg 2)"
+		echo $"Missing parameter 'IPv4-tunnel address' (arg 2)"
 		return 1
 	fi
 
@@ -360,14 +336,11 @@ ifup_ipv6_tunnel() {
 		return 1
 	fi
 
-	# Run IPv6 test
 	test_ipv6 || return 2
 
 
 	# Test, whether given IPv6 address is valid	
-	if ! testipv6_valid $routeipv6; then
-		return 2
-	fi
+	testipv6_valid $routeipv6 || return 2
 	
 
 	# enable general IPv6-over-IPv4 tunneling
@@ -397,33 +370,30 @@ ifdown_ipv6_tunnel() {
 
 	if [ -z "$device" ]; then
 		echo $"Missing parameter 'device' (arg 1)"
-		ifupdown_ipv6_tunnel_usage
 		return 1
 	fi
 
 	if [ -z "$addressipv4tunnel" ]; then
 		echo $"Missing parameter 'IPv4-tunnel address' (arg 2)"
-		ifupdown_ipv6_tunnel_usage
 		return 1
 	fi
 
 	if [ -z "$routeipv6" ]; then
 		echo $"Missing parameter 'IPv6-route' (arg 3)"
-		ifupdown_ipv6_tunnel_usage
 		return 1
 	fi
 
-	# Run IPv6 test
-	test_ipv6 || return 2    
+	test_ipv6 || return 2
+
 
 
 		# Delete a NBMA-styled tunnel
-		ifdown_ipv6_route $routeipv6::$addressipv4tunnel sit0
+		ifdown_ipv6_route $routeipv6 ::$addressipv4tunnel sit0
 		if [ $? -ne 0 ]; then
 			return 2
 		fi
 
-	# disable IPv6-over-IPv4 tunneling (if no longer a tunnel is up)
+	# disable IPv6-over-IPv4 tunneling (if this was the last tunnel)
 	ifdown_ipv6_autotunnel
 
 }	
@@ -431,7 +401,7 @@ ifdown_ipv6_tunnel() {
 
 ## Remove all IPv6 tunnels for a given tunnel endpoint
 #  $1: Interface (not used - dummy)
-#  $2: IPv4-tunneladdress 
+#  $2: IPv4-tunnel address 
 ifdown_ipv6_tunnel_all() {
 	local idtuall_device=$1
 	local idtuall_tunnel=$2
@@ -442,11 +412,10 @@ ifdown_ipv6_tunnel_all() {
 	fi
 
 	if [ -z "$idtuall_tunnel" ]; then
-		echo $"Missing parameter 'IPv4-tunneladdress' (arg 2)"
+		echo $"Missing parameter 'IPv4-tunnel address' (arg 2)"
 		return 1
 	fi
 
-	# Run IPv6 test
 	test_ipv6 || return 2
 
 
@@ -460,7 +429,7 @@ ifdown_ipv6_tunnel_all() {
 		fi
 	done
 
-	# disable IPv6-over-IPv4 tunneling (if no longer a tunnel is up)
+	# disable IPv6-over-IPv4 tunneling (if this was the last tunnel)
 	ifdown_ipv6_autotunnel
 	return 0
 }
@@ -485,7 +454,7 @@ test_ipv6_address_exists() {
 	if [ "$EXISTS_ipv6calc" = "yes" ]; then
 		# Using ipv6calc and compare against /proc/net/if_inet6
 
-		local convertresult="`LC_ALL=C ipv6calc --addr2if_inet6 $testaddr/$testprefix`"
+		local convertresult="`ipv6calc --addr2if_inet6 $testaddr/$testprefix`"
 		# Split in address, scope and prefix length
 		local test_addr="`echo $convertresult | awk '{ print $1 }'`"
 		local test_scope="`echo $convertresult | awk '{ print $2 }'`"
@@ -533,23 +502,15 @@ ifup_ipv6_real() {
 		return 1
 	fi
 
-	# Run IPv6 test
 	test_ipv6 || return 2
 
-	# Test, whether given IPv6 address is valid	
-	if ! testipv6_valid $address; then
-		return 2
-	fi
+	testipv6_valid $address || return 2
 
-	# Test status of interface
 	if test_interface_status $device; then
-		# Interface is already up
 		true
 	else
-		# no IPv4 for this interface, interface is still down, do up ...
 			ifconfig $device up
 
-			# Test, whether "up" has worked
 			if ! test_interface_status $device; then
 				echo $"Device '$device' enabling didn't work - FATAL ERROR!"
 				return 2
@@ -561,7 +522,7 @@ ifup_ipv6_real() {
 	local prefixlength_implicit="`echo $address | awk -F/ '{ print $2 }'`"
 	local address_implicit="`echo $address | awk -F/ '{ print $1 }'`"
 
-	# Only add, if address do not already exist
+	# Only add if address does not already exist
 	test_ipv6_address_exists $device $address_implicit $prefixlength_implicit
 	retval=$?
 	if [ $retval -lt 10 ]; then
@@ -589,7 +550,6 @@ ifdown_ipv6_real_all() {
 		return 1
 	fi
 
-	# Run IPv6 test
 	test_ipv6 || return 2
 
 
@@ -624,13 +584,9 @@ ifdown_ipv6_real() {
 		return 1
 	fi
 
-	# Run IPv6 test
 	test_ipv6 || return 2
 
-	# Test, whether given IPv6 address is valid	
-	if ! testipv6_valid $address; then
-		return 2
-	fi
+	testipv6_valid $address || return 2
 
 
 	# Extract address parts
@@ -664,7 +620,6 @@ testipv6_valid() {
 
 
 	if [ -z "$testipv6addr_valid" ]; then
-		# nothing for testing
 		return 2
 	fi
 
@@ -713,7 +668,6 @@ testipv4_globalusable() {
 
 
 	if [ -z "$testipv4addr_globalusable" ]; then
-		# nothing for testing
 		return 2
 	fi
 
@@ -823,23 +777,22 @@ ifup_ipv6to4() {
 		return 1
 	fi
 
-	# Run IPv6 test
 	test_ipv6 || return 2
 
 
-	# generate 6to4 address
+	# Generate 6to4 address
 	local prefix6to4="`create6to4prefix $localipv4`"
 	if [ $? -ne 0 -o -z "$prefix6to4" ]; then
 		return 2
 	fi
 
 	if [ -z "$localipv6to4suffix" ]; then
-		local address6to4="${prefix6to4}::1/48"
+		local address6to4="${prefix6to4}::1/16"
 	else
-		local address6to4="${prefix6to4}::${localipv6to4suffix}/48"
+		local address6to4="${prefix6to4}::${localipv6to4suffix}/16"
 	fi
 
-	# enable general IPv6-over-IPv4 tunneling
+	# Enable general IPv6-over-IPv4 tunneling
 	ifup_ipv6_autotunnel
 
 	ifup_ipv6_real sit0 $address6to4	
@@ -862,17 +815,15 @@ ifdown_ipv6to4_all() {
 		return 1
 	fi
 
-	# Run IPv6 test
 	test_ipv6 || return 2
 
 
-	# Get all configured 6to4 addresses
+	# Get all configured 6to4 addresses and delete them
 	LC_ALL=C ip addr show dev sit0 | grep inet6 | awk '{ print $2 }' | grep "^2002:" | while read ipv6to4addr; do
-		# And delete them
 		ifdown_ipv6_real sit0 $ipv6to4addr
 	done
 
-	# try to disable general IPv6-over-IPv4 tunneling
+	# Try to disable general IPv6-over-IPv4 tunneling
 	ifdown_ipv6_autotunnel
 
 }	
@@ -896,7 +847,6 @@ ifdown_ipv6to4() {
 		return 1
 	fi
 
-	# Run IPv6 test
 	test_ipv6 || return 2
 
 
@@ -908,9 +858,9 @@ ifdown_ipv6to4() {
 	fi
 
 	if [ -z "$localipv6to4suffix" ]; then
-		local address6to4="$prefix6to4::1/48"
+		local address6to4="$prefix6to4::1/16"
 	else
-		local address6to4="${prefix6to4}::${localipv6to4suffix}/48"
+		local address6to4="${prefix6to4}::${localipv6to4suffix}/16"
 	fi
 
 	ifdown_ipv6_real sit0 $address6to4	
@@ -918,7 +868,7 @@ ifdown_ipv6to4() {
 		return 2
 	fi
 
-	# try to disable general IPv6-over-IPv4 tunneling
+	# Try to disable general IPv6-over-IPv4 tunneling
 	ifdown_ipv6_autotunnel
 	if [ $? -ne 0 ]; then
 		return 2
@@ -945,17 +895,15 @@ ifup_ipv6_tunneldev() {
 	fi
 
 	if [ -z "$addressipv4tunnel" ]; then
-		echo $"Missing parameter 'IPv4-tunneladdress' (arg 2)"
+		echo $"Missing parameter 'IPv4-tunnel address' (arg 2)"
 		return 1
 	fi
 
-	# Run IPv6 test
 	test_ipv6 || return 2   
 
 
 
 		if ! test_interface_status $device; then
-			# Get default TTL
 			local ttldefault="`sysctl net.ipv4.ip_default_ttl | awk '{ print $3 }'`"
 			if [ -z "$ttldefault" ]; then
 				local ttldefault=64
@@ -990,7 +938,6 @@ ifup_ipv6_tunneldev() {
 
 			ifconfig $device up
 
-			# Test, whether creation did worked
 			if ! test_interface_status $device; then
 				echo $"Tunnel device '$device' bringing up didn't work - ERROR!"
 				return 2
@@ -1026,12 +973,10 @@ ifdown_ipv6_tunneldev() {
 		return 1
 	fi
 
-	# Run IPv6 test
 	test_ipv6 || return 2   
 
 
 	if test_interface_status $device; then
-		# Shut down tunnel
 		ifdown_ipv6_real_all $device
 	else
 		if [ "$device" != "sit0" ]; then
@@ -1043,7 +988,6 @@ ifdown_ipv6_tunneldev() {
 		if ip tunnel | grep -q "^$device:" ; then
 				ip tunnel del $device
 
-				# Test, whether removing did worked
 				if test_interface_status $device; then
 					false
 				fi
@@ -1055,3 +999,29 @@ ifdown_ipv6_tunneldev() {
 	return 0
 }	
 
+
+## Set IPv6 MTU for a device
+#  $1: Interface
+#  $2: IPv6 MTU
+ipv6_set_mtu() {
+	local device=$1
+	local ipv6_mtu=$2
+
+	if [ -z "$device" ]; then
+		echo $"Missing parameter 'device' (arg 1)"
+		return 1
+	fi
+
+	if [ -z "$ipv6_mtu" ]; then
+		echo $"Missing parameter 'IPv6 MTU' (arg 2)"
+		return 1
+	fi
+
+	# Check range
+	if [ $ipv6_mtu -lt 1280 -o $ipv6_mtu -gt 65535 ]; then
+		echo $"Given IPv6 MTU is out of range"
+		return 1
+	fi
+
+		sysctl -w net.ipv6.conf.$device.mtu=$ipv6_mtu >/dev/null
+}