Patent ID: 7570579

Claim:
A method for identifying failures in a network, comprising: detecting a port failure in a layer two switch that is connected to a plurality of layer three routers, wherein the layer three routers are configured to route traffic according to logical addresses included in the traffic and the layer two switch is configured to forward the traffic according to physical addresses included in the traffic; identifying an unreachable Media Access Control (MAC) address belonging to a router that is unreachable from the switch and associated with the port failure; and sending failure notifications to other ports on the switch that identify the unreachable MAC address associated with the port failure, the failure notifications being sent from the switch to the remaining reachable routers; wherein the failure notifications include the unreachable MAC address to identify the router as being unreachable from the switch, and wherein the failure notifications are configured to cause the remaining reachable routers to determine whether to update internal routing tables to route around an adjacency other than the switch.