Someone asked this question in one of his blog posts:
Yes, I’m seeing something like that now in the my dhdcp logs. Here is the actual message:
I think I know why this happened. Basically, the machine with MAC address of ’08:00:27:6e:61:b8′ used to have grab an IP address
from the pool. Then later on, I have created a reservation for it.
On Centos 7, the lease file is located at: /var/lib/dhcpd/dhcpd.leases. Here’s the duplicated lease for mathtXXX:
By removing the above block and restarting dhcpd service, the “uid lease duplicate” message no longer appears in the log.