| Feature | RARP | BOOTP | DHCP | |
|---|---|---|---|---|
| Relies on server to allocate IP addresses | Yes | Yes | Yes | |
| Encapsulates messages inside IP and UDP so that they can be forwarded to a remote server | No | Yes | Yes | |
| Client can discover its own mask/gateway/DNS/download server | No | Yes | Yes | |
| Dynamic address assignment from a pool of IP addresses without requiring knowledge of client MACs | No | No | Yes | |
| Allows temporary lease of IP address | No | No | Yes | |
| Includes extensions for registering client’s FQDN with a DNS | No | No | Yes |
ARP
Ethernet proto type: 0x0806
RARP
Same old ARP message, but the ARP request lists a MAC address target of its own MAC address and a target IP address of 0.0.0.0. RARP server on the same subnet. ARP reply, after entering the configured IP address in the Source IP address field.
BOOTP
IP+UDP header.
DHCP
IP+UDP header.
DHCP relay:
- set own IP address in gateway IP address (giaddr) field while relaying
- change the destination IP address to a LAN broadcast, and forward the packet
onto the client’s LAN