sysctl -w net.ipv4.conf.all.disable_ipv4=1
sysctl -w net.ipv6.conf.all.disable_ipv6=0
for link in $(ls /sys/class/net); do ip -6 addr add $(openssl rand -hex 2):$(openssl rand -hex 2):$(openssl rand -hex 2):$(openssl rand -hex 2):$(openssl rand -hex 2):$(openssl rand -hex 2):$(openssl rand -hex 2):$(openssl rand -hex 2)/128 dev $link; done
Everything should work perfectly forever right out of the box with the above setup.