|We use a hardware solution where I work that might interest you. It's an "ethernet tap" and it's made by NetOptics.|
You might want to take a look at their products, or another like it by a different manufacturer. They're certainly a lot more user friendly than doing a span (mirror) port on a cisco switch.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.