The requirements on IP routers are increasing for every new generation of designs. The driving forces behind this development are growing traffic volumes and demands for new services. We believe that a modular decentralized router design is well-suited to meet future requirements. However, a distributed design may, compared to a centralized system, introduce an additional cost for internal communication between the elements. In this paper we evaluate different transaction mechanisms for the internal communication. We study the suitability of reliable multicast for the internal distribution of large amounts of routing information. In particular, we evaluate NORM (NACK-Oriented Reliable Multicast) as a candidate protocol for our purposes.