I tried to use freeradius as dhcp server, but I have problems with ARP table upgrade.
Problem is, that if we set radius binary with capabilities, and then start it as root and then drop root privilleges and run as "freerad" user , it drop also its capabilities ...
Resolution is at: https://wiki.debian.org/Hardening/Daemons
-  that is configured
-  maybe secbits could help here - but I did not test it.