DHCPD is not re-using addresses

[CLOSE Dave]

The environment here is Fedora 23. One machine acts as DHCP server for 
the others (normal, I know). A small portion of each subnet is reserved 
for dynamic assignment, devices without reserved addresses.

When I run PXE on a new machine, I see the Anaconda (the Fedora 
installer) makes at least three requests for a dynamic address. So far 
as I can tell, all of the requests are identical. The sequence is 
something like this.

DHCPDISCOVER
DHCPOFFER on 10.76.148.235
DHCPREQUEST for 10.76.148.235
DHCPACK on 10.76.148.235
DHCPDISCOVER
DHCPOFFER on 10.76.148.248
DHCPREQUEST for 10.76.148.248
DHCPACK on 10.76.148.248
DHCPDISCOVER
DHCPOFFER on 10.76.148.249
DHCPREQUEST for 10.76.148.249
DHCPACK on 10.76.148.249
DHCPREQUEST for 10.76.148.248
DHCPACK on 10.76.148.248

Even though all the requests originate from the same MAC address, the 
DHCP server gives each request a unique response. As the address leases 
take time to expire, I quickly run out of available addresses. Much more 
quickly than I should.

I don't recall this happening when doing the same operations on a Fedora 
20 base, both DHCP server and PXE installations.
-- 
Dave Close, Thales Avionics, Irvine California USA.
cell +1 949 394 2124, dave.close at us.thalesgroup.com

"Technology has the shelf life of a banana." - Scott McNealy