Network Diagrams in Kivio.

Page Layout (Settings / Kivio)
    Page Size:  Screen
    Orientation:  Portrait
    All grid sizes to 1 cm.
    Turn on both snapping options

Tools  (Unfortunately, no good rackmount server stencils!)
    Stencil Set:  Hardware Collections / Computer Hardware
     (can add multiple.  May need another for arrows).
                  Dia / Network has network cloud + Ok tower
                  Dia / Sybase has crappy Disk
                  Misc / Nassi...  has squares and stuff useful for grouping

Many stencils do not have text capability.  Use free-standing text for these.

Changing stencil colors.  Select, then Format / Stencils-and-Connectors.

Free-standing text.  Ctrl-Shift-A then F2 then Click-and-drag outline.