HI all,     I have an odd problem ~    C35 controller - version 10.11  3805i APs  Fresh deployment  PSK SSID, Bridged@AP topology    Windows DHCP server  Allow/Deny filter added    The vast majority of users will receive IP addresses from the DHCP server with no problem at all.      Some users will not receive an IP address from the server.  Upon further inspection we can narrow it down like this :    1 - A user's lease expires, they are assigned a new IP address - this is visible in the DHCP active leases - but the user did not receive this address ?  We can delete the lease, release/renew the client, re-associate and still no IP address.    (this user had an DHCP address in the morning then they arrived - when the lease renewed, they had an error)    2 - A user comes in the morning, tries to connect and does not receive an IP address.    The user(s) has an APIPA address.    The user is authenticated to the WIFI  The users' PC is in the DHCP allow list  The user's PC is released/renewed - no change  The user's PC is dissociated and reassociated - no change    I have requested the lease to be changed from 8 days, to 8 hours - the client will action this afterhours.  DHCP service restarted - issue remains    Has anyone seen this issue before ?  Any advise on where to check as I checked through logs and setting and it all seems fine.  What is interesting is that out of the 100 users, about 80 of them connect to the wifi and this only happens to a random 3-6 users.  Not the same users...    I appreciate any responses,     thanks !