IP6_ADDR_1
SYS(fail, "ip -n %s -6 a add %s/128 dev veth1", ns1, IP6_ADDR_1);
SYS(fail, "ip -6 route add %s/128 dev veth2 %s", IP6_ADDR_1, vrf);
SYS(fail, "ip -6 route add %s/128 dev veth4 via %s", IP6_ADDR_1, IP6_ADDR_3);
IP6_ADDR_1, IP6_ADDR_GRE);
#define IP6_ADDR_SRC IP6_ADDR_1