These are great icons for network diagrams from Russ White. Much more useful for all diagrams purposes than most other icons.
I’ve developed this set of vendor neutral network icons for drawing diagrams in presentations, books, and the like. I’m placing them here in the public domain in four different formats
Network Icons – ‘net work : http://rule11.us/net-icons/
Personally, I use simple shapes and colours for my diagrams for simplicity but I suspect these will appeal to people who are Visio-centric in their workflow.