虚拟网络交换机技术

为了提高网络的可靠性，常常在网络中采用双交换机冗余，同时还使用STP、VRRP等技术，然而STP和VRRP等需要复杂的配置。虚拟交换机技术把两台在软硬件相似的交换机结合在一起形成逻辑上的交换机，从而使得STP、VRRP等配置问题大大简化。虚拟交换机中的交换机协商主、从角色，主交换机控制二层和三层协议的运行，主、从交换机间通过虚拟交换链路交换信息；但是对于用户数据，主、从交换机都将会处理。虚拟交换技术减少了故障后的网络收敛时间，包括虚拟交换链路上的一些不必要的流量。

Virtual Switch Technology

In order to increase network reliability, network operators usually deploy redundant switches in the network, and they use STP and VRRP technologies, but STP and VRRP require complicated configuration. Virtual switch technology combines a pair of switches, which are similar in hareware and software, into a single virtual logic switch, thus to simplify STP and VRRP configuration. In virtual switch, these two switches negotiate their principal and subordinate roles, that is, one becomes the active switch, and the other becomes the standby switch, the active switch controls the VS, and runs the Layer 2 and Layer 3 control protocols for the switching modules on both switch. Both switches perform user packet forwarding. VS reduces the converging time when the network fails, including the unnecessary data traffic in the virtual switch link between two switches.