一题很迷茫的题

single

<P>前几天讨论过，路由器的开机启动顺序是，ROM---TFTP---FLASH-----NVRAM</P><P>可是这题</P><P>QUESTION NO: 16<BR>If NVRAM lacks boot system commands, where does the router look for the Cisco<BR>IOS by default?<BR>A. ROM<BR>B. RAM<BR>C. Flash<BR>D. Bootstrap<BR>E. Startup-.config<BR>Answer: C<BR>为什么</P><P>启动一台新的路由器（没有IOS）和启动一台有配置的路由器，有什么区别吗？</P>

王晓强

<P><FONT size=3>*RAM-Sometimes called DRAM for dynamic random-access memory,RAM is used by the router just as it is used by any other computer:for working storage.The running or active configuration file is stored here.</FONT></P><P><FONT size=3>*ROM-This type of memory(read-only memory)stores s bootable IOS image,which typically is not used for normal operation.ROM contains the code that is used to boot the router until the router knows where to get the full IOS image or as a backup bootable image,in case there are problems.</FONT></P><P><FONT size=3>*Flash memory-Either an EEPROM or PCMCIA card,Flash memory stores fully functional IOS images and <FONT color=#ff0066>is the default location where the router gets ite IOS at boot time</FONT>.Flash memory also can be used to store any other files,including configuration files.</FONT></P><P><FONT size=3>*NVRAM-Nonvolatile RAM stores the initial or startup configuration file.</FONT></P><P><FONT size=3>The boot process follows this basic litany:</FONT></P><P><FONT size=3>1.The router performs a power-on self-test(POST)to discover and verify the hardware.</FONT></P><P><FONT size=3>2.The router loads and runs bootstrap code from ROM.</FONT></P><P><FONT size=3>3.The router finds the IOS or other software and loads it.</FONT></P><P><FONT size=3>4.The router finds the configuration file and loads it into running config.</FONT></P><P><FONT size=3>其中的第三步find IOS，如果是新的路由器默认情况下是在Flash中查找，如果是有配置的才会去查找TFTP上的IOS.所以要具体的看题目，这题选Ｃ没错！路由器的开机启动顺序是，ROM---TFTP---FLASH-----NVRAM也是对的！</FONT></P>