单项选择题
A. To provide a monitoring mechanism for networks in switched environments.
B. To manage VLANs across multiple switches.
C. To prevent switching loops in networks with redundant switched paths.
D. To segment a network into multiple collision domains.
E. To prevent routing loops in networks.
单项选择题 By default, which of the following factors determines the spanning-tree path cost?（）
单项选择题 Which OSI layer header contains the address of a destination host that is another network?（）
单项选择题 You have set up an Internet based FTP server, where people can upload and download files. In terms of the OSI model, what is the highest layer used during the FTP sessions.（）