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

    host1 [ label="Dualstack host"];
    host2 [ label="Dualstack host"];
    host3 [ label="Dualstack host"];
    router [ label="IPv6 & IPv4 router"];

    v4internet [ label="IPv4 Internet", shape="egg" ];
    v6internet [ label="IPv6 Internet", shape="egg" ];

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

    host1--switch1;
    host2--switch1;
    host3--switch1;

    switch1--router;
    router--v4internet;
    router--v6internet;

}