Can a peer to peer replication be setup so as to use different ports for replicating from node 1 (4331021)

A master-master replication is set up so as to use one port across all nodes. The question users sometimes have is whether different port numbers can be used for replication in forward and backward direction. Say, can one port # be used for replication from node 1 to node 2 and another one for vice versa?

General information.

In a true bi-directional replication environment, the same port is used on all nodes.  In such environment applications may access the same schema on all nodes and have conflict resolution routines set up to resolve conflicts. The following are the reasons why different ports cannot be used:

1. The conflict resolution routines are only feasible for replication between same port numbers. For example, it is possible to configure a conflict resolution setup for replication between node 1 and node 2 on port 2100. If an attempt is made to setup a conflict resolution on primary Shareplex instance on port 2100 and secondary Shareplex instance on port 2200, this will fail.

2. When using different ports on these nodes, the Capture process on each node will loopback the transactions posted by other port back to the other node as Capture only ignores the transactions applied by Post from the same port and not from Post from other ports.

There is one scenario where it is possible to set up different ports for replicating in different directions between nodes. If an entirely different set of schema is replicated between node 1 and node 2 and vice versa, then it will not matter whether same port is used in both directions or not.  Such type of replication is not considered a peer to peer replication and does not require any conflict resolution.