Pros and cons of setting up cascading replication using same and different port between source and intermediate and intermediate and target Shareplex.
Here are advantages and disadvantages of both approaches:
If using same port, only one sp_cop runs on B and there is only one Shareplex schema. This results in less resources usage and less maintenance. But you can never have a two way replication between A and B as enabling SP_OCT_REPLICATE_POSTER on B can result in transaction loopback to A when post applies transactions on B. Shareplex cannot be shutdown on B as messages would stop flowing from A to B and onwards.
If using different ports, there will be two Shareplex instances on B and would involve more effort to set this up and more effort would be required to manage these two. But it has the advantage of more granular management as it is possible to shutdown one replication stream (say A to B) and still have the other replication stream running (say B to C).
