RARP and BOOTP were simply the first steps in figuring out a method to deliver IP configuration information. After RARP was developed, it became apparent that it had a couple of major shortfalls. First, a RARP server could only operate on a single subnet. Second, it lacked the critical ability to provide any IP configuration information other than the IP address.
Although BOOTP provided a vast improvement over RARP, it also suffered some serious shortfalls. First, the BOOTP database was a static text file. This meant that administrators needed to maintain the file by hand as changes were made to the network. A simple change like replacing a host’s network interface card required the administrator to update the BOOTP database file. Another shortfall was the inability to dynamically allocate and distribute IP addresses. In the age of depleted IP address space, dynamic IP addressing was a critical feature.
Seeing this, the IETF started work to create a new protocol that would overcome these shortfalls: Dynamic Host Configuration Protocol (DHCP).