Patent ID: 8300523
Filing Date: 2012-10-30
Classification: H04L

Abstract:
1. A method comprising: configuring a maximum number of links allowed in a link aggregate group (LAG) on each of a network device and a standby network device to one; configuring a maximum number of links allowed in the link aggregate group (LAG) on a dual-homed device to at least two, wherein the network device provides a first downlink connection with the dual-homed device and the standby network device provides a second downlink connection to the dual-homed device, and wherein the dual-homed device associates the first and second downlinks links with the link aggregate group; forwarding traffic received by the network device on the first downlink connection with the dual-homed device to an uplink connection with a network core; detecting a failure on the uplink connection with the network core; and in response to detecting the failure, notifying the standby device of the failure, through an inter-chassis control channel between the network device and the standby device and sending a message to the dual-homed device triggering the dual-homed device to begin forwarding traffic to the network core via the second downlink connection between the standby device and the dual-homed device, wherein the inter-chassis control channel is physically independent of the uplink connection and the first and second downlink connections, wherein a state synchronization is performed between the network device and the standby device through sending a periodic heartbeat message from the network device to the standby device over the inter-chassis control channel.