Existing mechanisms of IP fast reroute

The slow convergence of existing routing protocols after link or node failure became a problem. As a solution IP fast Reroute mechanisms have been developed. IP Fast Reroute mechanisms offer rapid network recovery after link or node failure. The basic idea of the IP Fast Reroute is to pre-calculate alternative backup path in advance. In the case of failure IP Fast Reroute Mechanism will use pre-calculated backup path to bypass failed link or node. In this paper we focus on description of well-known IP Fast Reroute mechanisms that are currently being used in real ISP networks but also describe IP Fast Reroute mechanisms that are under investigation and offer new approach. We test LFA IPFRR mechanism in simulator GNS3. Results proof, that IPFRR technology has significant impact on time of network recovery.