1. [单选题]扩展ACL和标准ACL的区别（）。
A. 标准的ACL在禁止和允许方面比扩展的ACL更高的精度
B. 扩展的ACL核查数据包的源地址和目标地址和端口号
C. 他们都可以查端口号
D. 他们都可以查特殊协议和其他参数
2. [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.
3. [单选题]You are a senior network administrator at Ezonexam, and while performing the password recovery procedure on your 2500 series Cisco router, you type in the following command:o/r 0x2142
A. What is the purpose of this command?
B. It is used to restart the router.
C. It is used to bypass the configuration in NVRAM.
D. It is used to enter ROM Monitor mode.
E. It is used to view the lost password.
F. It is used to save the changes to the configuration.
