|
Ethernet Automatic Protection Switching (EAPS) is used to create a fault tolerant topology by configuring a primary and secondary path for each VLAN. It was invented by Extreme Networks. The idea is to provide highly available Ethernet switched rings (commonly used in Metro Ethernet). Other implementations include Ethernet Protection Switching Ring (EPSR〔(How to configure EPSR )〕) by Allied Telesis, "Rapid Ring Protection Protocol"() by Huawei/H3C, "ZTE Ethernet Smart Ring" (ZESR) by ZTE. == Operation == A ring is formed by configuring a Domain. Each domain has a single "master node" and many "transit nodes". Each node will have a primary port and a secondary port, both known to be able to send control traffic to the master node. Under normal operation, the secondary port on the master is blocked for all protected vlans. When there is a link down situation, the devices that detect the failure send a control message to the master, and the master will then unblock the secondary port and instruct the transits to flush their forwarding databases. The next packets sent by the network can then be flooded and learned out of the (now enabled) secondary port without any network disruption. Fail-over times are demonstrably in the region of 50ms. The same switch can belong to multiple domains and thus multiple rings. However, these act as independent entities and can be controlled individually. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ethernet Automatic Protection Switching」の詳細全文を読む スポンサード リンク
|