单项选择题
A.The PC has connectivity with a local host.
B.The PC has connectivity with a Layer 3 device.
C.The PC has a default gateway correctly configured
D.The PC has connectivity up to Layer 5 of the OSI model
E.The PC has the TCP/IP protocol stack correctly installed.
单项选择题 根据下图显示的拓扑结构和路由器配置，一个在该LAN上的主机正在通过INTERNET访问一个FTP服务器。下列地址中哪个可以作为路由器发送到该目的服务器的数据包的源地？（）
单项选择题 How does using the service password encryption command on a router provide additional security?（）
多项选择题 A network administrator wants to ensure that only the server can connect to port Fa0/1 on a Catalyst switch. The server is plugged into the switch Fa0/1 port and the network administrator is about to bring the server online. What can the administrator do to ensure that only the MAC address of the server is allowed by switch port Fa0/1 (Choose two.)（）。