2012年思科认证（CCNA）考试练习题精选10
2012年思科认证考试备考的朋友，不用为了查找复习资料而烦恼，小编特为广大考生朋友们搜集了有关2012年思科认证（CCNA）考试练习题，帮助大家复习，祝大家考试顺利。
46. The PING command makes use of what ICMP parameter (PING命令使用了什么I C M P参数.？
A. Redirect
B. Source quench
C. Echo reply
D. Destination unreachable
47. ICMP Redirect is sent by (ICMP重定向由什么发出.？
A. A host to the gateway
B. A gateway to the host
C. A router to another router
D. A router to a network
48. How many layers does the TCP/IP protocol suite have, compared to the OSI reference model (和O S I参考模型相比，T C P / I P协议具有几层)？
A. TCP model has 4, OSI model has 6
B. TCP model has 7, OSI model has 8
C. TCP model has 4, OSI model has 7
D. TCP model has 7, OSI model has 4
49. What OSI reference model layer do sockets function at (套接字在O S I参考模型的哪层运作)？
A. Application
B. Presentation
C. Session
D. Transport
E. Network
F. Data link
G. Physical
50. What function do sockets perform (套接字的功能是什么)？
A. They make remote functions appear local, transparent to the user
B. They transfer files to and from remote nodes
C. They make the transport layer independent
D. They allow multiple applications to share the same connection to the network