单项选择题
A. A Catalyst switch cannot have ISL and IEEE 802.1q trunks enabled.
B. All Catalyst switches support ISL trunking.
C. A Catalyst switch will report giants if one side is configured for ISL while the other side is not.
D. ISL trunking requires that native VLANs match.
E. None of the other alternatives apply
单项选择题 A new Company switch was just configured using the "switchport trunk native vlan 7" command. What does this interface command accomplish？（）
单项选择题 You need to configure a new Company switch to support DTP. Which DTP switchport mode parameter sets the switch port to actively send and respond to DTP negotiation frames？ （）
单项选择题 While using a packet analyzer， you notice four additional bytes being added to the packets in the Company network. Which protocol inserts a four byte tag into the Ethernet frame and recalculates CRC value？ （）