多项选择题
An administrator is unsuccessful in adding VLAN 50 to aswitch. While troubleshooting the problem, the administrator views the output of the show vtp status command, which is displayed in the graphic. What commands must be issued on this switch to add VLAN 50 to the database?（）
A. Switch(config-if)# switchport access vlan 50 B. Switch(vlan)# vtp server C. Switch(config)# config-revision 20 D. Switch(config)# vlan 50 name Tech E. Switch(vlan)# vlan 50 F. Switch(vlan)# switchport trunk vlan 50
多项选择题 Which statements describe the routing protocol OSPF?（）
多项选择题 What information does a router running a link-state protocol use to build and maintain its topological database?（）
多项选择题 OSPF routing uses the concept of areas. What are the characteristics of OSPF areas?（）
