graph G {
    node [ shape="box"];


    v6host [ label="IPv6 only host"];
    v4host [ label="IPv4 only host"];

    switch1 [ label="Network Switch", shape="oval" ];
    switch2 [ label="Network Switch", shape="oval" ];

    nat64gw [ label="NAT64 translator", rank=max ];


    v6host--switch1;
    v4host--switch2;

    switch1--nat64gw;
    switch2--nat64gw;



}