we had an IP address conflict take down the network earlier. It has since been resolved and the MAC address pointed to an AMP Wireless WAP. The WAP is connected to an HP Procurve 2810 (I think - it's downstairs). We had this issue some time back as well and traced it to a TrendNet WAP, which happened to be connected to the same switch. Both WAPs are (were) configured with a static IP and DHCP was disabled on both (verified by logging in). Disconnecting the WAP solved it.
It happened after I moved the WAP from one location in the office to another. Since I moved it, I had to connect to a different port but the same switch. Once I plugged it in and connected it to the port, almost everyone received an IP conflict message and could not access network or internet resources.
All that said, could it be the switch? The WAP had been plugged in for several months, and had been moved once before just last week, without issue.
Thanks for any insight. This was a pain and would like to avoid it happening again.