What hubs/switches have you used or are used at your work place and do you program the ports yourself or use a particular type of software? At the place where I work they used to use cisco switches and now have moved over to extreme switches. In case some of you don't know what extreme is (beside a pain in the backside sometimes) they call them intelligent switches designed to run two different ip address such as a 10 and 128 address through the same switch. However what do you do when a PC is producing two MAC address and the extreme switch blocks it and shuts down that port switch??