1. Add a live subnet in IPAM say '10.100.1.0/24'. It should have some live IPs(eg: 10.100.1.1) and their MACs should be brought into IPAM through subnet scan.
2. Put some Static ARP entries in a switch for the above responded IPs(eg: 10.100.1.1) but with some other MAC.
3. Add this switch as a 'Neighbor Device' for the subnet '10.100.1.0/24'.
4. Trigger a subnet scan.
This should simulate IP conflict in IPAM.