Recently my company migrates all PCs to XP. We start to see connectivity problems with Cisco 3500XL switch. I did some test in the lab and determined it is the NIC driver because prior to XP we were using Win2K and we have no problem. If I use a different switch model, it works. If I use a different brand of NIC, it works with 3500XL. If I lower to 10/half or 10/full, it works. Only 100 Mbps doesn't seem to work. Anyone see the same problem? Thanks.