本人以前通过CCNA，提供一些建议。
　　　
　　条件：
　　
　　英语一定要好
　　
　　对OSI参考模型，TCP／IP模型有很好的掌握
　　
　　使用过CISCO的低端路由器
　　
　　对交换机的运作功能有一些基础
　　
　　A.CCNA Certification Exam Objective
　　
　　The CCNA (640-407)exam will consist of a combination of the following objective
　　
　　1.Identify and describe the functions of each of the seven layers of the OSI reference
　　model
　　
　　2.Describe connection-oriented network service and connectionless network service
　　,and identif the key differences between them.
　　
　　3.Describe data link addresses and network addresses,and identify the
　　
　　key differences between them
　　
　　4.Define and describe the function of a MAC address.
　　
　　5.Define flow control and describe the three basic metthods used in netwoeking
　　
　　6.Differentiate between the following WAN services:frame relay,isdn/lapd,hdlc,&ppp
　　
　　7.Log into a router in both user and privileged modes
　　
　　8.Use the context-sensitive help facility
　　
　　9.Use the command history and editing features
　　
　　10.Examine router elements(RAM,ROM,CDP,show)
　　
　　11.Manage configuration files from the privileged exec mode
　　
　　12.Control router passwords,identification and banner
　　
　　13.Identify the main cisco IOS commands for router startup
　　
　　14.Check an initial configuration using the setup command
　　
　　15.Copy and manipulate configuration files
　　
　　16.List the commands to load cisco IOS software from:flash memory,a tftp server,or
　　ROM
　　
　　17.Prepare to backup,upgrade,and load a backup Cisco IOS software image
　　
　　18.List the key internetworking functions of the OSI network layer and
　　how they are performed in a router
　　
　　19.Describe the two parts of network addressing,then identify the part
　　
　　s in specific protocl address examples
　　
　　20.List problems that each routing type encounters when dealing with topology
　　changes and describe techniques to reduce the number of theseproblems

　　21.Explain the services of separate and integrated multiprotocol routing
　　
　　22.Describe the different classes of IP address
　　
　　23.Configure IP address
　　
　　24.Verify IP address
　　
　　25.Prepare the initial configuration of your router and enable ip
　　
　　26.Add the RIP routing protocol to your configuration
　　
　　27.Add the IGRP routing protocol to your configuration
　　
　　28.List the required IPX address and encapsulation type
　　
　　29.Enable the Novell IPX protocol and configure interfaces
　　
　　30.Monitor Novell IPX operation on the router