IP4_ADDR_2
SYS(fail, "ip -n %s a add %s/24 dev veth2", ns2, IP4_ADDR_2);
SYS(fail, "ip route add %s/32 dev veth1 %s", IP4_ADDR_2, vrf);
SYS(fail, "ip route add default dev veth1 via %s %s", IP4_ADDR_2, vrf);
SYS(fail, "ip route add %s/32 dev veth4 via %s", IP4_ADDR_2, IP4_ADDR_3);