I have several 10/100 3750's I just bought to replace my current switches. I'm going to stack the switches with stacking cables. Most of the devices on my network run at 100 mbps. However, I want to attach my servers and an external tape backup at 1000 mbps. Can I just plug my 1000 mbps devices into the SFP ports, or are these ports only to be used to attach switches together? Thanks in advance.