US Patent:
20140192817, Jul 10, 2014
Inventors:
- Armonk NY, US
Venkatesan Selvaraj - Sunnyvale CA, US
Shoou Yiu - San Jose CA, US
Yu H. Guo - San Jose CA, US
Assignee:
INTERNATIONAL BUSINESS MACHINES CORPORATION - Armonk NY
International Classification:
H04L 12/56
Abstract:
Physical links between an access switch and a pair aggregation switches are aggregated into a virtual link aggregation group (vLAG). Each aggregation switch is a local switch to itself and a remote switch to the other aggregation switch. Each aggregation switch maintains a state machine including initialization, local-up, remote-up, and formed states. In the initialization state, the physical link between the access switch and each aggregation switch is down, and the vLAG is down. In the local-up state, just the physical link between the access switch and the local switch is up, and the vLAG is down. In the remote-up state, just the physical link between the access switch and the remote switch is up, and the vLAG is down. In the formed state, the physical link between the access switch and each aggregation switch is up, and the vLAG is up.