Abstract: The system, method, and article of manufacture of the present invention allows multiple customers connected to a common external network to each implement a layer 2 redundancy protocol, such as the spanning tree protocol, in order to prevent layer 2 loops. Accordingly, a method is presented for providing an independent loop free layer 2 topology between a external network and a customer network comprising tagging control packets originating on the customer network with a unique identifier and tunneling the control packets received from the customer network between a plurality of boundary interface devices at the external network such that the control packets are routed back to the customer network based on the presence of the unique identifier in the control packet. The layer 2 redundancy protocol on the customer network converges based at least in part on the presence of control packets appearing on more than one port on the customer network.

Abstract: Techniques that assist in processing of failure detection protocol (FDP) packets. Techniques are provided that assist a CPU of a network device in processing incoming FDP packets. In one embodiment, only a subset of FDP packets received by the network device is forwarded to the CPU for processing, the other FDP packets are dropped and not forwarded to the CPU. In this manner, the amount of processing that a CPU of the network device has to perform for incoming FDP packets is reduced. This enables the network device to support newer FDPs with shorter periodic interval requirements.

Abstract: Disclosed is a technique for facilitating software upgrade for a switching system comprising a first management processor and a second management processor and a set of one or more line processors, the techniques comprising receiving a signal to perform a software upgrade for a line processor from the set of line processors, and performing a software upgrade for the line processor without substantially affecting packet switching performed by the switching system.

Abstract: Techniques for computing a path for a local repair connection to be used to protect a connection traversing an original path from an ingress node to an egress node. The computed path originates at a node (start node) in the original path and terminates at another node (end node) in the original path that is downstream from the start node. A Constraint Shortest Path First (CSPF) algorithm may be used to compute the path. The computed path is such that it satisfies one or more constraints and does not traverse a path from a first node in the original path to a second node in the original path, wherein the first and second nodes are upstream from the start node in the original path and the second node is downstream from the first node in the original path. A local repair connection may then be signaled using the computed path.