Network Processors (NPs) are set to play a key role in the next generation of networking technology. They have the performance of ASIC-based routers whilst offering a high degree of programmability. However, the programmability potential of NPs can only be realised with appropriate software. In this paper we argue that specialised software to support runtime reconfiguration is needed to fully exploit the potential of NPs. We first justify supporting runtime reconfiguration on NPs by offering real-world scenarios and discussing the issues associated with these. We then demonstrate how runtime reconfiguration can be achieved in practice through a case study of our component-based programming approach on the Intel IXP2400 NP.