In IP-over-WDM networks, a logical IP network has to be routed on top of a physical optical fiber network. An important challenge hereby is to make the routing survivable. We call a routing survivable if the connectivity of the logical network is guaranteed in case of a failure in the physical network. In this paper we describe FastSurv, a local search algorithm which can provide survivable routing in the presence of physical link failures. The algorithm can easily be extended for the case of node failures and multiple simultaneous link failures. In a large series of test runs, we show that FastSurv is much more scalable with respect to the number of nodes in the network than current state-of-the-art algorithms, both in terms of solution quality and run time.