1. [单选题]默认情况下，RIP定期发送路由更新的时间是（）
A. 15S
B. 30S
C. 60S
D. 90S
2. [单选题]下列关于路由器和交换机的描述中，错误的是（）
A. 路由器可以用来连接internet
B. 二层交换机可以用来实现“异地网络”互连
C. 路由器可以用来做路径选择
D. 交换机可以转发广播
3. [单选题]After connecting a PC to an available port on a switch, you find that the PC can not access any of the resources on the LAN. No other PC's connected to the switch appear to be having any issues. What is the most likely cause for this problem?
A. The router lacks a routing table entry for the new host
B. The host switch port is assigned to the incorrect VLAN
C. The host MAC address is incorrectly configured
D. A STP instance for the new host has not been initialized
E. The switch does not have the MAC address hard coded in the CAM table.
4. [单选题]在OSPF的完全存根区域中，使用以下哪种LSAType报文或其它方式与区域间通信：（）
A. LSAType1.2
B. LSAType3
C. LSAType4
D. 默认路由：0.0.0.0
5. [多选题]In which Spanning-Tree states does a switch port learn MAC addresses? (Select two)
A. Blocking
B. Listening
C. Forwarding
D. Learning
E. Relaying
