I've having an issue with one of my AP's. Last week I noticed that one of my APs is connected at 100mpbs. I've tried all of the usual troubleshooting steps, powercycle, changing ports, etc. I used a cable tester on the cat 6 line and everything looks good. I did get 1gbps to stick for a few hours, but the AP rebooted on its own and dropped back down to 100mbps.