PASS 607，做下来感觉实在不难，有三分之二是在BIBLE中见过的。一开使做的很快，做到48题出现实验题竟然还剩一个多小时！，感觉这么快做有点对不起那1000块便在实验题上做了20分钟。
　　开始考试时，小姐还告诉我考试时间可以加30分钟结果一考显示时间为75分钟，立即叫他来调然后她输入一个叫什么热线电话密码显示密码错误！！输了好几次都不行，嘴里便嘟囔着怎么回事靠！
　　时间在流失呀，我赶紧叫她打电话问问。问过之后才知道每次考试的密码不一样，心里想你怎么才知道。幸好题目简单！！
　　实验题两道一是设密码，跟BIBLE里的比就换了ROUTER名字叫什么BLUE RED GREEN！！（CCNA真要完了！！），一道是配ROUTING PROTOCOL ，注意我配好之后，PING远段S1口竟燃PING不通，PING S0和E0通怀疑是模拟器BUG。
　　下面谈谈学习经历：
　　我看的是CISCO CCNA EXAM#640-507 由WENDELL ODEM编的书是老了点，但很使用，将原理分析很透彻，并举了很多例子，又有题目并有答案。（英文电子版，看了我一个半月！眼镜又加厚了几圈（开玩笑），但里面确实有很多句式比较复杂的英文，向英文比较好的兄弟门推荐，最好通过CET-6的（又开玩笑了）
　　然后便是搜集习题楼，什么BOSON的，CCNA SIMULATION，TESTKING，LANPUB，CISCOWIND，FOUNDLI，CHINAITLAB的BIBLE
　　BOSON上的题目最好都能看看他的解释其它几份BIBLE都有错！碰到自己答案跟BIBLE上不一样，可以贴到论坛上让大家讨论。
　　最主要的还是看书！！在论坛上见过一些贴，问的比较呆，好象
　　没看过书就看BIBLE了。
　　下面是我认为争议较大的一些问题答案：（可能仍有问题）
　　1.What are four functional characteristics of the network layer of the OSI
　　model?
　　A.It uses a two part address
　　B.It maintains routing tables
　　C.It uses broadcast addresses
　　D.It establishes network addresses
　　E.It provides access to the LAN media
　　F.It provides media independence for upper layers
　　G.It provides path selection for internetwork communication
　　答，ABDG，不光NETWORK使用BROATCAST ADDRESS，DATA LINK也用。
　　2.In which three situations is a hold-down timer reset? (Choose three.)
　　A. When the hold-down timer expires.
　　B. When infinity is finally defined as some maximum number.
　　C. When the router exchanges update summaries at area borders.
　　D. When the router detect faulty LSPs propagating through the internetwor
　　k.
　　E. When another update is received indicating a new route with a better m
　　etric.
　　F. When another update is received indicating the original route to the n
　　etwork has been restored.
　　G. When the router receives a processing task proportional to the number
　　of links in the internetwork.
　　答，AEG，有人说在SYBEX书上见过此题答案不过我认为是这个。
　　因为一个HOLDDOWN TIMER RESET在两种情况下产生一个是THE HOLDDOWN TIMER EXPIRES 一个是ANOTHER UPDATE IS RECEIVED INDICATING NET STATES CHANGE。
　　3.which command displays all routed protocols and interfaces
　　on which the protocol is enabled?
　　A.show protocols
　　B.show protocol brief
　　C.show interfaces protocol
　　D.show interfaces
　　E.show routed
　　F.show routed interfaces
　　答，A
　　) what does igrp use to determine the best path to a
　　
　　destination?
　　A:the highest metric value
　　B:the lowest composite metric value
　　C:the lowest hop-count and delay
　　D:the highest bandwidth and reachability
　　E:the lowest administrative distance
　　答，B，首先IGRP也用METRIC值，当有多条路由到达时便取最小值他是一个由BANDWITDH，DELAY，RELIABILITY，LOAD和MTU共同决定所以是一个COMPOSITE METRIC value。
　　Which two statements about a reliable connection oriented data transfer are true? (Choose two)
　　A.Recipients acknowledge receipt of data
　　B.When tankers are filled to capacity, datagrams are discarded and not retransmitted
　　C.Windows are used to control the amount in outstanding unacknowledged data segments
　　D.If the sender a timer expires before receipt of an acknowledgment the sender drops the connection
　　E.The receiving device waits for acknowledgments from the sending device before accepting more data segments
　　答，AC，A是接受者确认受到DATA，对！接受者再把确认送给SENDER，这是一个SYMMERIC过程，D指一个TIMER过期就会DOWN CONNECTON，他只会重发！CONNECTON-ORIENT 的SETUP 和TERMINATON都有过程的（一个是三个过程一个是四个过程）
　　Which two statements about frame tagging are true? (Choose two )
　　A.A filtering table is developed for each switch
　　B.Frame tagging assigns a unique user defined ID to each frame
　　C.A unique identifier is placed in the header of each frame as it is forwarded between switches
　　D.Frame tagging is a technique that examines particular inFORMation about each frame based on user defined offsets
　　答，BC，BOSON上有也有解释！
　　which wan technology uses high-quality digital lines and IS packet switched?
　　A FDDI
　　B ISDN
　　C ATM
　　D frame relay
　　答，C，可以传送高数字话的以及INTERMRDIATE SYSTEM包的我认为是C
　　which command should you use to configure a router so that it can become a TFTP server host for a router system image that is run in flash?
　　a. copy flash tftp
　　b. config tftp server
　　c. write network
　　d. tftp-server system
　　e. setup server tftp
　　答，D，书上有，
　　you telnet to a host on a remoter network .which mac address will be present in the arp table when you issue the show arp command?
　　A. MAC address of the destination host Ethernet port
　　B. MAC address of the local router Ethernet port
　　C. MAC address of the destination host serial port
　　D. MAC address of the local router serial port
　　答，B，我曾被此题迷惑，想想是包的被路由过程没搞清楚当你发一个TELNET包时，网络层肯定是目的地址，但第一步是找最近路由DHCP告之GATEWAY地址，通过ARP找路由器所以是本地路由器的以太网址。
　　which frame relay feature allows the point-to-point frame relay pvc between router a and router b to be indetified at router a sa 100 and at router b as 2007
　　A. locally significant DLCI
　　B. globally significant dlc
　　C. locally significant lmi
　　D. globally significant lmi
　　答，A，DLCI只对本地来说是唯一的，而为了方便我们采用GLOBALLY ADDRESSING来确定一个ROUTER 一个DLCI。