IP6_ADDR_GRE
IP6_ADDR_1, IP6_ADDR_GRE);
SYS(fail, "ip a add %s dev gre6_dev", IP6_ADDR_GRE);
ns1, IP6_ADDR_GRE, IP6_ADDR_6, vrf);
ns2, IP6_ADDR_GRE, IP6_ADDR_8, vrf);
SYS(fail, "ip -n %s -6 route del %s/128 dev veth5 %s", ns1, IP6_ADDR_GRE, vrf);
SYS(fail, "ip -n %s -6 route del %s/128 dev veth7 %s", ns2, IP6_ADDR_GRE, vrf);
SYS(fail, "ip -n %s -6 route add unreachable %s/128 %s", ns1, IP6_ADDR_GRE, vrf);
SYS(fail, "ip -n %s -6 route add unreachable %s/128 %s", ns2, IP6_ADDR_GRE, vrf);