Hi,
Something I have been sitting on a while (testing of course) is my patch to 
ISC DHCP3 (seems to apply fine to 3.0.x and 3.1.x) so that you can use OMAPI 
to get a MAC -> IP result.

Others have grumbled about this[1] before and it started bothering me so I 
clobbered omapi.c to give me what we wanted (support to set 'state' of 
lease).

Feedback welcome, a description of how to use the patch is on my website[2].

Cheers

Alex

[1] http://marc.info/?l=dhcp-hackers&m=118314732327554&w=2
[2] http://www.digriz.org.uk/dhcp-omapi#OMAPIhwaddrQuerySupport