IP4_ADDR_8
SYS(fail, "ip -n %s a add %s/24 dev veth8", ns3, IP4_ADDR_8);
SYS(fail, "ip route add %s/32 dev veth5 via %s %s", IP4_ADDR_8, IP4_ADDR_6, vrf);
SYS(fail, "ip route add %s/32 dev veth7 %s", IP4_ADDR_8, vrf);
ns2, IP4_ADDR_GRE, IP4_ADDR_8, vrf);