ip tuntap add name tap0 mode tun
ip link set tun0 up
ip addr add 10.0.0.1/24 dev tun0

ip netns add smoltcp
ip link set tun0 netns smoltcp
ip netns exec smoltcp bash
watch -n 0.1 ip netns exec smoltcp ss -tani

ip netns exec smoltcp tcpdump -n -i tun0
