Active Directory Series 13: Replication of AD

Through the previous 12 lectures, in fact, we have been discussing the logical structure of the Active Directory more, today we talk about the replication of ad issues. In fact, for each DC, there will be a database file, it is the ad database, see Activity Directory Series one: Basic concepts

The ad database is divided into four directory partitions, as shown in the following illustration:

The first two partitions are replicated at the forest level, that is, the schema partition and the configuration partition. The domain partition is replicated at the domain level. The application partition is an optional copy that can be configured on its own and not discussed here.

(i) Replication within the site

If there are multiple DCs at the same time in a single domain environment, each DC synchronizes three partitions at the forest and domain level. If there are multiple DCs in a multi-domain environment, there will be multiple replication topologies. As shown in the following illustration:

There are three kinds of replication topologies on the diagram above, the first is forest-level replication, replicated between all DCs, and the second is the replication topology of domain A's domain partition, replicated between all domain A DCS, and the third is the replication topology of domain B's domain partition, replicated across all domain B DCs. If a GC exists in the DC above, the replication topology above will also change because the GC is a special role that will have a subset of the domain partition objects and the object properties for all domains.

In fact, as we all see, our replication topology is a two-way loop (guaranteed fault tolerance), which is automatically generated by the KCC process on each DC.