# Three non-overlapping groups

group.dmz { fill: #ffa070; }
group.outer { fill: #f07070; }

( Internal Network:
  [ Workstation ]
) { fill: #70b070; }
  
[ Workstation ] --> [ Inner Firewall ]

( DMZ:
[ Inner Firewall ] -> [ Proxy ]
--> [ Outer Firewall ]
[ Proxy ] --> [ Database\n Server ]
) { class: dmz; }

( Outer: 
  [ Internet ]
) { class: outer }

[ Outer Firewall ] --> [ Internet ]