IP6_ADDR_3
SYS(fail, "ip -n %s -6 a add %s/128 dev veth3", ns2, IP6_ADDR_3);
SYS(fail, "ip -6 route add %s/128 dev veth4", IP6_ADDR_3);
SYS(fail, "ip -6 route add %s/128 dev veth4 via %s", IP6_ADDR_1, IP6_ADDR_3);
SYS(fail, "ip -6 route add %s/128 dev veth4 via %s", IP6_ADDR_2, IP6_ADDR_3);