High-performance interconnection networks like InfiniBand, ASI, Autonet andMyrinet have the property of link level flow control. As such alterating the routing function while the network is operational is a complex process, because the danger of packet deadlocks must be addressed. Over the last 5-6 years this problem has been addressed and solved by the research community. This chapter collects several proposals for updating a routing function in interconnection networks after the occurrence of a topological change. Both traditional and recent reconfiguration schemes are covered, and the selection includes both technology-dependant and generic techniques.