Even in well managed Large ISP networks, failures of links and routers are common. Due to these failures the routers update their routing tables. Transient loops can occur in the networks when the routers adapt their forwarding tables. In this paper, a new approach is proposed that lets the network converge to its optimal state without loops and the related packet lossless. The mechanism (OUTFC-Ordered Updating Technique with Fast Convergence) is based on an ordering of the updates of the forwarding tables of the routers and fast convergence. Typically we have chosen a Network consisting of routers and Link costs for simulation. Link failures are simulated. Avoiding transient loops in each case is demonstrated, by constructing a Reverse Shortest PathTree (RSPT).