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

    x520_1 [ label="X520: IPv4" ];
    x520_2 [ label="X520: IPv6" ];
    x520_nsg [ label="X520: Controller" ];

    netpfga1 [ label="NetFPGA Port 1" ];
    netpfga2 [ label="NetFPGA Port 2" ];
    netpfga3 [ label="NetFPGA Port 3" ];



    subgraph cluster_esprimo {
        label="Load generator";

        x520_1;
        x520_2;
    }

    subgraph cluster_nsg {
        label="NetFPGA Host";

        netpfga1;
        netpfga2;

        netpfga3--x520_nsg;
    }

    x520_1--netpfga1;
    x520_2--netpfga2;



}