Same-region replication
In same-region replication (SRR), both the source and target MSK clusters are in the same AWS Region. Same-region replication is useful for data aggregation, distributing data to partners, or migrating between clusters.
Key differences from cross-region replication:
The source cluster does not require multi-VPC private connectivity.
You do not need to attach a resource-based permissions policy to the source cluster.
You must provide security groups for both the source and target clusters. The subnets you select for the source and target clusters must be in the same Availability Zones.
The source cluster can still be accessed by other clients using the unauthenticated auth type.