A routing device receives a forwarding entry for forwarding a first flow and stores it locally. When the device is a key forwarding device of a first flow, the stored forwarding entry includes first and second forwarding entries. When the device is located in a primary forwarding path but is not the key forwarding device, the stored forwarding entry comprises one forwarding entry having a priority higher than a predefined minimum value. The device receives a first flow. When the stored forwarding entry comprises one forwarding entry having a priority higher than the minimum value and a link connected to an egress port in the forwarding entry has failed, the device sets the priority of the forwarding entry as the minimum value, and returns the first flow to the key forwarding device to trigger it to forward the first flow according to the second forwarding entry.