I've got a Cisco3560 POE Switch that we have been migrating users off of to other switches in our facility. What we have been doing to perform this migration is to perform the "sh mac-address table" command, log the MAC addresses, and then look these up on our DHCP server to determine the connected device. I have four devices remaining on this switch, 4 ports are still showing active and flashing green lights, but the above command never shows a MAC address for these ports. I've ran the command at numerous times during the day and it never shows a connected MAC address. Before I take off through our large manufacturing facility and start following physical cable runs, I wanted to know if anyone had an other ideas of how I can determine some more information about these connected devices?