IP6_ADDR_6
SYS(fail, "ip -n %s -6 a add %s/128 dev veth6", ns2, IP6_ADDR_6);
SYS(fail, "ip -6 route add %s/128 dev veth5 %s", IP6_ADDR_6, vrf);
SYS(fail, "ip -6 route add %s/128 dev veth5 via %s %s", IP6_ADDR_7, IP6_ADDR_6, vrf);
SYS(fail, "ip -6 route add %s/128 dev veth5 via %s %s", IP6_ADDR_8, IP6_ADDR_6, vrf);
SYS(fail, "ip -6 route add %s/128 dev veth8 via %s", IP6_ADDR_6, IP6_ADDR_7);
ns1, IP6_ADDR_GRE, IP6_ADDR_6, vrf);