You begin migrating to a load-balanced array of Front End Servers by deploying the Front End Servers that will make up the array. Until you change the FQDN entries in the Active Directory Domain Services, all users will continue to use the existing single Front End Server. Meanwhile, you can test the new Front End Servers individually by using a few host file changes, ensuring minimal downtime.
After you have validated the individual Front End Servers, you insert the load balancer in front of these new servers and configure it. Again, because you have not yet modified the production DNS records, end users are still unaffected. With some additional host file record changes, you can now test the load balanced environment and validate failover behavior on each of the Front End Servers.
After the load balancing behavior has been validated, the final step is to cut over to this new environment by removing the host file entries and changing the correct DNS entries in your production environment.
If you encounter any issues during cutover, you can quickly revert to the single Front End Server. When the array is performing correctly, you can decommission the single Front End Server. The rest of this document will describe each phase of this process in detail.