Patent ID: 7869351
Filing Date: 2011-01-11
Classification: H04J,H04L

Abstract:
1. A method comprising: establishing multiple layer 2 network links between a first data communication device and a second data communication device; enabling layer 3 network communications over each of the multiple layer 2 network links by establishing a plurality of layer 3 network communications interfaces in the first data communication device, each respective one of the layer 3 network communication interfaces for communication over a corresponding one of the multiple layer 2 network links; assigning by the first data communication device a plurality of layer 3 network addresses to the layer 3 network communications interfaces, each one of the layer 3 network communications interfaces being assigned a different one of the layer 3 network addresses than the other layer 3 network communications interfaces; monitoring a health status of the multiple layer 2 network links by executing a BFD (Bidirectional Forwarding Detection) session in the first data communication device, the BFD session communicating over the layer 3 network communications interfaces using a BFD protocol, the BFD protocol being a protocol for fault detection; updating a forwarding table in the first data communication device to route any traffic to the second data communication device over at least one backup layer 3 network communications interface instead of over at least one primary layer 3 network communications interface in response to detecting a failure in at least one of the multiple layer 2 network links with the BFD session, the at least one primary layer 3 network communications interface being for communication over the at least one of the multiple layer 2 network links, the layer 3 network communications interfaces including the at least one backup layer 3 network communications interface and the at least one primary layer 3 network communications interface, the forwarding table identifying how to route traffic received by the first data communication device from a network; receiving at least one data packet from a third data communication device at the first data communication device; identifying by the first data communication device whether the at least one data packet is routable through the second data communication device to a remote device based on the forwarding table, the remote device being identified by a remote network address in the at least one data packet; and routing the at least one data packet by the first data communication device over at least one backup layer 3 network communications interface based on the forwarding table, wherein routing the at least one data packet includes: selecting a private layer 3 network address associated with a target layer 3 network communication interface in the second data communication device from the forwarding table, the private layer 3 network address being associated with the second data communication device and the at least one backup layer 3 network communications interface in the forwarding table, the layer 3 network addresses including the private layer 3 network address; and forwarding the at least one data packet to the private layer 3 network address from the at least one backup layer 3 network communications interface over a corresponding one of the layer 2 network links to the target layer 3 network communication interface at the second data communication device.