Why I see other unicast from a switched port?

[frank]

I use the span on Cat5500 to troubleshoot a problem, after I looking into the trace, I see some unicast from the switched port.

Shouldn't I only see the unistcast in/out from the device on that port and broadcast or multicast? Why I seeing some other unicast from that port?

[Prashanth Krishnappa]

Unicast flooding is the most common cause. The following page should help

http://www.cisco.com/warp/public/473/143.html