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

    v6host1 [ label="IPv6 only host" color="blue" ];
    v6host2 [ label="IPv6 only host" color="blue" ];
    v6host3 [ label="IPv6 only host" color="blue" ];
    v4host1 [ label="IPv4 only host" color="yellow" ];
    v4host2 [ label="IPv4 only host" color="yellow" ];
    v4host3 [ label="IPv4 only host" color="yellow" ];

    switchv6 [ label="Network Segment", shape="oval" ];
    switchv4 [ label="Network Segment", shape="oval" ];

    nat64gw [ label="Router /\nNAT64 translator", rank=max ];

    v6host1--switchv6;
    v6host2--switchv6;
    v6host3--switchv6;

    v4host1--switchv4;
    v4host2--switchv4;
    v4host3--switchv4;

    switchv4--nat64gw;
    switchv6--nat64gw;
}