单项选择题
A. It tags the data frame with VLAN information and recalculates the CRC value
B. It encapsulates the data frame with a new header and frame check sequence
C. It modifies the port index of a data frame to indicate the VLAN
D. It adds a new header containing the VLAN ID to the data frame
E. None of the other alternatives apply
单项选择题 Two Company switches are connected via a trunk link. In this network， the original frame is encapsulated and an additional header is added before the frame is carried over a trunk link. At the receiving end， the header is removed and the frame is forwarded to the assigned VLAN. This describes which technology？（）
多项选择题 When the Catalyst switch R1 is enabled to use VTP， which information does it advertise on its trunk ports？（）
多项选择题 Switch R1 is configured with VTP. Which two VTP modes will make R1 capable of creating and deleting VLANs on itself？ （）