Patent ID: 8929205
Filing Date: 2015-01-06
Classification: H04L

Abstract:
1. A system including: a first apparatus having first ports and a first stack port; a second apparatus having second ports and a second stack port; and a plurality of logical lines including physical lines which are collectively handled as a link aggregation, wherein, when the first apparatus and the second apparatus work virtually as one unit, the first apparatus and the second apparatus are connected at the first stack port and the second stack port, the plurality of logical lines include at least one of the physical lines as a transfer physical line and at least one of the physical lines as a standby physical line, and during normal operation, the transfer physical line is connected to the first ports of the first apparatus which are set to active, and the standby physical line is connected to the second ports of the second apparatus which are set to backup, and when traffic passing through the stack ports between the first and second apparatuses exceeds a predetermined threshold owing to a link down of the transfer physical line, all the second ports of the second apparatus are set to be active ports, and all the first ports of the first apparatus are set to be backup ports to switch the standby physical line to the transfer physical line.