enabled ip6tables-based firewalling in first two IPv6 scenarios

testing/tests/ipv6/net2net-ikev1/pretest.dat

@@ -1,5 +1,5 @@
-moon::echo "1" >/proc/sys/net/ipv6/conf/all/forwarding
-sun::echo "1" >/proc/sys/net/ipv6/conf/all/forwarding
+moon::/etc/init.d/iptables start 2> /dev/null
+sun::/etc/init.d/iptables start 2> /dev/null
 alice::"ip route add fec2:\:/16 via fec1:\:1"
 moon::"ip route add fec2:\:/16 via fec0:\:2"
 sun::"ip route add fec1:\:/16 via fec0:\:1"