Holger Linke builds a transactional replication topology with a couple of twists:
Bidirectional transactional replication is a specific Transactional Replication topology that allows two SQL Server instances or databases to replicate changes to each other. Each of the two databases publishes data and then subscribes to a publication with the same data from the other database. The “@loopback_detection” feature ensures that changes are only sent to the Subscriber and do not result in the changes being sent back to the Publisher.
The databases that are providing the publication/subscription pairs can be hosted either on the same SQL instance or on two different SQL instances. The SQL instances can either be SQL Server on-premise, SQL Server hosted in a Virtual Machine, SQL Managed Instance on Azure, or a combination of each. You just have to make sure that the instances can connect to each other. If you add a subscription by using the fully-qualified domain name (FQDN), verify that the server name (@@SERVERNAME) of the Subscriber returns the FQDN. If the Subscriber server name does not return the FQDN, changes that originate from that Subscriber may cause primary key violations.
Read on for the scripts.