IP4_ADDR_VETH2
server_fd = start_server(AF_INET, SOCK_STREAM, IP4_ADDR_VETH2,
SYS(fail_close_server_ns, "ip -4 addr add " IP4_ADDR_VETH2 "/24 dev veth2");
cfg->server_addr = IP4_ADDR_VETH2;
cfg->tunnel_server_addr = IP4_ADDR_VETH2;
"ip -4 route add " IP4_ADDR_VETH2 " mtu 1450 dev veth1");
"ip -4 addr add " IP4_ADDR_VETH2 "/24 dev veth2");
.tunnel_server_addr = IP4_ADDR_VETH2,