TechTalk – Rockwell : EtherNetIP BOOTP Setting Up IP Address Using BOOTP
The Bootstrap Protocol (BOOTP) is a computer networking protocol used in the Internet Protocol (IP) networks to assign an IP address to network devices from a configuration software or server. For our case, the software would be Rockwell BOOTP-DHCP Server software.

When the Allen-Bradley EtherNetIP card (connected to an Ethernet network) is powered up for the first time or if it is in BOOTP mode, the card broadcasts BOOTP messages onto the Ethernet network (that it is connected to) to request for an IP address assignment to the card. Using the Allen-Bradley BOOTP-DHCP Server software, you can assign an IP address to the EtherNetIP card.

This article and YouTube video shows you the steps in assigned IP adress and eventually stopping the BOOTP service from the EtherNetIP card.