Bootpd
BOOTPd lets client workstations using Bootstrap Protocol request their configuration information. If a client machine is configured for BOOTP, a BOOTP request is broadcast over the network each time the machine starts.
The BOOTP request contains the MAC (Media Access Control) address of the machine (physical hardware address). When Bootpd is enabled, it responds to requests if the client’s MAC address is found in the boottab configuration file. 
Requirements
- You must enable Bootpd in InetD on at least one machine in the network. It is best to enable Bootpd on several machines so that if one machine fails to respond, the configuration information is available on other machines on the network.
- You must create a configuration file, bootptab, in the system\HUMMINGBIRD\Connectivity\version\InetD directory, where version is the version number of your Hummingbird product. You must use the same file on all machines running BOOTP.
Comparison to RARP
The Reverse Address Resolution Protocol (RARP), also lets a client determine its IP address when the MAC (Media Access Control) address is known. The difference between RARP and BOOTP is that RARP is a hardware, link-level protocol instead of an IP/UDP protocol. This means that RARP can be implemented only on local hosts on the same subnet.