多项选择题
A. It can be used between Cisco and non-Cisco switch devices.
B. It calculates a new CRC field on top of the existing CRC field.
C. It adds 4 bytes of protocol-specific information to the original Ethernet frame.
D. It adds 30 bytes of protocol-specific information to the original Ethernet frame.
多项选择题 Which of the following trunking modes are unable to request their ports to convert their links into trunk links？ （）
单项选择题 If you were to set up a VLAN trunk over a Fast Ethernet link on switch R1， which trunk mode would you set the local port to on R1 if you wanted it to respond to requests from its link partner （R2） and become a trunk？ （）
单项选择题 You are the network administrator at Company and switch R1 is configured as shown below： Interface gigethernet 0/1 Switchport mode trunk Switchport trunk encapsulation dot1q Switchport trunk native vlan 5 If untagged frames are arriving on interface gigethernet 0/1 of R1， which of the following statement are correct？（）