1. [单选题]下面对Cisco2621路由器和Cisco2501路由器描述中，错误的是（）
A. Cisco2621路由器的可扩展性优于Cisco2501路由器
B. Cisco2621是模块化路由器
C. Cisco2501上提供一个100Mbit/s的快速以太网端口
D. Cisco2501是固定端口的路由器
2. [单选题]You are a systems administrator and you are about to assign static IP addresses to various servers on your network. For the network 192.168.20.24/29 the router is assigned to the first usable host address, while the last usable host address goes to your Sales server. Which one of the following commands would you enter into the IP properties box of the sales server?
A. IP address: 192.168.20.14 Subnet Mask: 255.255.255.248 Default Gateway: 192.168.20.9
B. IP address: 192.168.20.254 Subnet Mask: 255.255.255.0 Default Gateway: 192.168.20.1
C. IP address: 192.168.20.30 Subnet Mask 255.255.255.248 Default Gateway: 192.168.20.25
D. IP address: 192.168.20.30 Subnet Mask 255.255.255.240 Default Gateway: 192.168.20.17
E. IP address: 192.168.20.30 Subnet Mask 255.255.255.240 Default Gateway: 192.168.20.25
3. [单选题]On a half-duplex Ethernet LAN, two hosts attempt to send data simultaneously, resulting in a collision. Following this collision, what will the hosts do? (Select all valid answers)
A. The destination host sends a request to the source for retransmission.
B. The jam signal indicates that the collision has been cleared.
C. The hosts will attempt to resume transmission after a time delay has expired.
D. An electrical pulse indicates that the collision has cleared.
E. The router on the segment will signal that the collision has cleared.
F. F. The hosts will do nothing, as the higher layers are responsible for data error correction and re-transmission.
4. [单选题]RIP协议负载均衡的路径数量为（）
A. 无限制
B. 最多4条
C. 最多5条
D. 最多6条
5. [单选题]对于使用链路状态路由协议的路由器如何选择最佳路线到达子网，下列哪项是正确的（）
A. 路由器会发现链路状态数据库中的最佳路由
B. 通过针对链路状态数据库中的信息运行SPF算法，路由器会计算出最佳路由
C. 路由器将比较每个邻居接收到的更新中为子网列出的标准，并挑选最佳标准路由
D. 路由器会使用具有最低条数的路径
