多项选择题 Flex Links are a pair of a Layer 2 interfaces (switchports or port channels), where one interface is configured to act as a backup to the other. Which two statements are correct regarding Flex Links?（）

多项选择题 What four functions does Web Cache Communication Protocol (WCCP) incorporate?（）

单项选择题 A virtual storage area network (VSAN) is a collection of ports from a set of connected Fibre Channel switches, that form a virtual fabric. Which technology allows centralized storage services to be shared across different VSANs?（）