digraph G {
    node [ shape=box ]
    rankdir=LR;

    client1 [ label="IPv4 client 1\nPrivate IP" ];
    client2 [ label="IPv4 client 2\nPrivate IP" ];
    clientn [ label="IPv4 client n\nPrivate IP" ];
    nat_gw  [ label="NAT gateway\nPublic IP"  ];
    target  [ label="IPv4 Server\nPublic IP" ];

    {client1, client2, clientn}->nat_gw;
    nat_gw->target;
    target->nat_gw;



}