digraph firewall {
rankdir=LR;
graph [bgcolor=transparent];
node [shape=ellipse style=filled fontname=Arial fontsize=12]; /* default */
edge [arrowhead=none]; /* default */
subgraph cluster_0 {
label="Ports";
node [color=green];
port_ [label=""];
}
subgraph cluster_1 {
label="Services";
node [color=yellow];
service_ [label=""];
}
subgraph cluster_2 {
label="Sources";
node [color=orange];
source_ [label=""];
}
subgraph cluster_3 {
label="Networks";
node [shape=record color=lightblue];
network_ [label="|{}"];
}
port_
->
service_
;
service_
->
source_
[taillabel=
headlabel=
];
source_
->
network_
;
}