What is essential to perform before starting a DHCP service migration?

Stopping the existing DHCP service is essential before starting a DHCP service migration because it ensures that no new leases or updates are processed by the old server during the migration process. This step minimizes the risk of data inconsistencies and lease conflicts, as the new server will need to take over the management of client addresses and settings. Without halting the existing service, there could be active leases or configurations that may not be transferred or recognized correctly by the new DHCP instance, leading to potential network issues.

While backing up the server databases, notifying users about downtime, and running a migration report are all important steps associated with a smooth migration process, they do not directly prevent problems during the transition itself. Stopping the existing DHCP service is a critical safeguard to ensure that the migration is seamless and that the new environment is set up correctly without interference from the old DHCP settings.