After you set up your sites and deploy your domain controllers, there shouldn't be much else to do but bask in a job well done. One or two things may crop up, though, that demand your attention.
Given enough time, the KCC will create an intra-site replication topology that converges changes as rapidly as possible. The ISTG will do the same for inter-site replication.
If a domain controller goes down, it may take a while for the KCC to recognize the problem and begin work to heal the replication ring. If the KCC or ISTG fails to respond in time to forestall an emergency, you can intervene and create a connection manually.
When you build a manual connection, you interfere with the automatic ...