METHOD AND SYSTEM OF SHORTEST PATH BRIDGING (SPB) ENHANCED RESILIENCE WITH LOOP MITIGATION

摘要

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.

主权项

1. A method to forward Ethernet frames at a node in a network supporting an implementation of shortest path bridging (SPB) protocol, wherein the node contains a filtering database (FDB) to guide Ethernet frame forwarding, wherein the FDB update is coordinated through a digest exchange between the node and one or more neighboring nodes, the method comprising:
starting a shortest path computation for the node (referred to as the computing node), the shortest path computation selecting at least a shortest path to each destination node in the network, wherein a neighboring node on the shortest path to reach each node is recorded; computing a downstream loop-free alternate (LFA) node for a destination node, if one exists, wherein the LFA node is downstream of the computing node, but not on the selected shortest path to the destination node from the computing node and the computing node has an existing database digest agreement with the LFA node, such that forwarding Ethernet frame from the computing node to the destination node through the LFA node is known not to cause a forwarding loop, and wherein being downstream means the LFA node is closer to the destination node than the computing node; and forwarding an unicast Ethernet frame with a destination media access control (MAC) address corresponding to the destination node through the LFA node when connectivity to the neighboring node on the computed shortest path is detected to be in an abnormal state.