I have strange situation. I have one central switch cisco 3850 which works as DHCP server and wireless MC. Also there are 14 access switches also 3850 which work as wireless MAs. I have one SSID in which clients are working. There are Windows notebooks and smatphones connected to this SSID. So notebooks behave strangly. They get IP address from DHCP. Work about 30 minutes and then error "IP conflict with [MAC]" shows up((( Notebook changes its IP, then works about 30 min and again conflict and again change IP. The most strange is that MACs in errors are MACs from these 14 switches, of its physical ports!!! When I delete vlan for SSID from these switches but leave 2 switches with the vlan, notebooks work about 2 hours and then again conflict((( Could anyone propose a possible solution? I tried to change DHCP hardware to another router - no help. The same result.
I think that DHCP can not check IPs because of Windows firewalls. But it is very weak explanation. Moreover WiFi points and IP phones also get IPs from DHCP and no problems(((