A method forward Ethernet frames at a node in a network supporting an implementation of shortest path bridging (SPB) protocol is disclosed. The method starts with a shortest path computation for the node (referred to as the computing node). The shortest path computation selects at least a shortest path to each destination node in the network, where a neighboring node on the shortest path to reach each node is recorded. Then it computes a downstream loop-free alternate (LFA) node for a destination node, where the LFA node is downstream of the computing node but not on the selected shortest path to the destination node from the computing node. Then when connectivity to the neighboring node on the computed shortest path is detected to be abnormal, the node forwards an Ethernet frame with a destination media access control (MAC) address corresponding to the destination node through the LFA node.