( DMZ:
  [ Backend ]
  [ Database ]
  [ Proxy ]
  [ Server ]
)

[ Proxy ] --> [ Check ]
[ Proxy ] --> { flow: south; } [ Database ]
[ Proxy ] --> [ Server ]
[ Check ] --> [ Backend ]
[ Database ] --> [ Backend ]

( DMZ1:
  [ 1Backend ]
  [ 1Database ]
  [ 1Proxy ]
  [ 1Server ]
)

[ 1Proxy ] --> [ 1Check ]
[ 1Proxy ] --> { flow: south; } [ 1Database ]
[ 1Proxy ] --> [ 1Server ]
[ 1Check ] --> [ 1Backend ]
[ 1Database ] --> [ 1Backend ]
[ 1Proxy ] --> [ 1Check ]
[ 1Proxy ] --> { flow: south; } [ 1Database ]
[ 1Proxy ] --> [ 1Server ]
[ 1Check ] --> [ 1Backend ]
[ 1Database ] --> [ 1Backend ]