1. [多选题]Two stations on the Ezonexam LAN transmit at the same time, resulting in a collision. What happens when a collision occurs on the network? (Choose all that apply)
A. Each device on the Ethernet segment stops transmitting for a short time.
B. A jam signal informs all devices that a collision occurred.
C. When data transmission resumes, the devices that were involved in the collision have priority to transmit.
D. The devices that are involved in the collision stops transmitting for a short time.
E. The collision invokes a random back-off algorithm.
2. [单选题]两台路由器直连到一起，应该使用的线缆为（）
A. 交叉线缆
B. 直通线缆
C. 反转线缆
D. 任意线缆
3. [单选题]关于OSPF中DR的说法不正确的是（）
A. 通过hello报文选举DR
B. 如果某路由器优先级比DR优先级高，但启动晚，它会抢占原来的DR自己成为DR
C. 一个广播类型网络中只能有一个DR
D. 一旦DR失效，BDR接替DR的工作，并重新选举一个BDR
4. [单选题]RIP路由协议认为“网络不可到达”的跳数是：()
A. 8
B. 16
C. 24
D. 100
5. [单选题]当拓扑信息完成交换，相邻路由器具有相同的LSDB时，下列哪项OSPF邻居状态是希望得到的()
A. 2-WAY
B. FULL
C. Exchange
D. Loading
6. [单选题]OSPF骨干区的区域编号为（）
A. 0.0.0.1
B. 255
C. 0.0.0.0
D. 255.255.255.255
7. [单选题]关于静态NAT，下面（）说法是正确的。
A. 静态NAT转换在缺省情况下24小时后超时
B. 静态NAT转换从地址池中分配
C. 静态NAT将内部地址一对一静态映射到内部全局地址
D. CISCO路由器缺省使用了静态NAT
8. [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(module router)
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
9. [单选题]EIGRP的管理距离（）
A. 90
B. 100
C. 110
D. 120
10. [单选题]What is the purpose of the spanning-tree algorithm in a switched LAN?
A. To provide a monitoring mechanism for networks in switched environments.
B. To manage VLANs across multiple switches.
C. To prevent switching loops in networks with redundant switched paths.
D. To segment a network into multiple collision domains.
E. To prevent routing loops in networks.
