Modern modelling languages provide dedicated features to support the detailed design of complex systems from different domains. Nevertheless, especially general-purpose languages provide extensive syntactical expressiveness that, in some cases, may be hard to align with well-defined semantics. This is often inevitable due to the fact that, in order for model-driven approaches to be fruitful, modelling activities should require a lower effort than code-based approaches. In the case of UML and component-based design, precise syntactical definition of the number of component and port instances building up the system is provided. How component instances are explicitly connected to each other via ports is left as a semantic variation point in order for the modeller to freely interpret the related metamodel semantics. On the one hand, in order to allow model analysability, simulation and generation of target code, ad-hoc choices regarding this semantics need to be taken. On the other hand, leaving the burden of this task to the developers is often unthinkable for complex industrial systems (composed by a number of components and connections in the magnitude of 10^4 and above). Therefore we propose a set of semantic rules for the establishment of explicit links between component instances and provide a solution for the automatic generation of these links by applying the defined rules.