多项选择题
A. TK2(config-if)# switchport access vlan 50
B. TK2(vlan)# vtp server
C. TK2(config)# config-revision 20
D. TK2(config)# vlan 50 name Tech
E. TK2(vlan)# vlan 50
F. TK2(vlan)# switchport trunk vlan 50
多项选择题 There are 2 switches in the Testking LAN, with no routers. Ports 1, 2 & 3 are assigned to VLAN 1 in switch 1 and 2 and ports 4, 5 & 6 are assigned to VLAN 2 in both switches. These two switches are connected together via a trunked link. Which of the conditions below would verify trunk and VLAN operation?（）
单项选择题 A TestKing.com technician is troubleshooting connectivity problems between two routers that are directly connected through the serial line. The technician notices that the serial line is up but cannot see any neighbors displayed in the output of the show cdp neighbors command. In which OSI layer is the problem most likely occurring?（）
单项选择题 Which layer of the OSI reference model is responsible for ensuring reliable end-to-end delivery of data?（）