Network-wide migrations of a running network, such as the replacement of a routing protocol or the modification of its configuration, can improve the scalability, manageability, security or the performances of the entire network. However, such migrations are an important source of concerns for network operators as the reconfiguration campaign can lead to long and service-affecting outages. In this work, we propose several techniques to address the problem of seamlessly (i.e. without loosing IP packets) modifying the configuration of commonly used routing-protocols.