ip -net "$nsr2" addr add 192.168.100.2/24 dev tun0
ip netns exec "$nsr2" sysctl net.ipv4.conf.tun0.forwarding=1 > /dev/null
-ip -net "$nsr2" link add name tun6 type ip6tnl local fee1:2::2 remote fee1:2::1
+ip -net "$nsr2" link add name tun6 type ip6tnl local fee1:2::2 remote fee1:2::1 || ret=1
ip -net "$nsr2" link set tun6 up
ip -net "$nsr2" addr add fee1:3::2/64 dev tun6 nodad
ip -net "$nsr1" route change default via 192.168.100.2
ip -net "$nsr2" route change default via 192.168.100.1
-ip -6 -net "$nsr1" route change default via fee1:3::2
-ip -6 -net "$nsr2" route change default via fee1:3::1
+
+# do not use "route change" and delete old default so
+# socat fails to connect in case new default can't be added.
+ip -6 -net "$nsr1" route delete default
+ip -6 -net "$nsr1" route add default via fee1:3::2
+ip -6 -net "$nsr2" route delete default
+ip -6 -net "$nsr2" route add default via fee1:3::1
ip -net "$ns2" route add default via 10.0.2.1
ip -6 -net "$ns2" route add default via dead:2::1
ip -net "$nsr1" link add name tun6.10 type ip6tnl local fee1:4::1 remote fee1:4::2
ip -net "$nsr1" link set tun6.10 up
ip -net "$nsr1" addr add fee1:5::1/64 dev tun6.10 nodad
-ip -6 -net "$nsr1" route change default via fee1:5::2
+ip -6 -net "$nsr1" route delete default
+ip -6 -net "$nsr1" route add default via fee1:5::2
ip netns exec "$nsr1" nft -a insert rule inet filter forward 'meta oif tun6.10 accept'
ip -net "$nsr2" link add link veth0 name veth0.10 type vlan id 10
ip -net "$nsr2" route change default via 192.168.200.1
ip netns exec "$nsr2" sysctl net.ipv4.conf.tun0/10.forwarding=1 > /dev/null
-ip -net "$nsr2" link add name tun6.10 type ip6tnl local fee1:4::2 remote fee1:4::1
+ip -net "$nsr2" link add name tun6.10 type ip6tnl local fee1:4::2 remote fee1:4::1 || ret=1
ip -net "$nsr2" link set tun6.10 up
ip -net "$nsr2" addr add fee1:5::2/64 dev tun6.10 nodad
-ip -6 -net "$nsr2" route change default via fee1:5::1
+ip -6 -net "$nsr2" route delete default
+ip -6 -net "$nsr2" route add default via fee1:5::1
if ! test_tcp_forwarding_nat "$ns1" "$ns2" 1 "IPIP tunnel over vlan"; then
echo "FAIL: flow offload for ns1/ns2 with IPIP tunnel over vlan" 1>&2