I have 2 ASA5510's, identical configs. I was having speed issues with one, so I unplugged it and plugged the second one in. The second one is much faster than the first one. Both are connecting at 100 MBps Full duplex, and the configs are identical. Our ISP couldn't explain why this was the case, and recommended to try getting an answer from Cisco. We didn't purchase any extra support, but it should be under warranty. I have been told that I need to purchase support and open a TAC, but I haven't had much success in navigating Cisco's site to do this. Has anyone experienced something similar, or have a recommendation?