ISC DHCP server config option get-lease-hostnames
The get-lease-hostnames statement
The get-lease-hostnames statement is used to tell dhcpd whether or not to look up the domain name corresponding to the IP address of each address in the lease pool and use that address for the DHCP hostname option. If flag is true, then this lookup is done for all addresses in the current scope. By default, or if flag is false, no lookups are done.
The idea is to perform a reverse DNS lookup to find the corresponding hostname in place of the provisioning system or the client... For documentation purpose only.