First of all thanks MT for adding DHCP conflict detection. Looks like some polishing is still needed. As far as i know DHCP server trying to check IP in use or not using ICMP and ARP response before give a lease. Unfortunately DHCP server not checking idle hotspot sessions when client is disconnected but hotspot session is active until Idle timeout will kill that session. ARP has a record with DC (D - dynamic C - complete) status. That is why we having sometimes ARP with flapping MAC address (Current one and Old one from hotspot)
Can somebody fix that?